Zoom lens system

Abstract

A zoom lens system comprises from the object side to the image side: a first lens unit of a positive refractive power; a second lens unit of a negative refractive power; and a third lens unit of a positive refractive power; wherein one of the first and third lens units is shiftable along the optical axis of the lens system in both of the zooming operation and the focusing operation, and the second lens unit is also shiftable along the optical axis of the lens system in the zooming operation.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a zoom lens system and more particularly to a zoom lens system applicable to a video camera or a still video camera.

2. Description of the Prior Art

Recently, since the compactness of a plurality of electric circuits and integrated circuits contained in a video camera system and the like are improved, the lens system contained in such a camera system possesses a large proportion of the size and weight of the entire camera system. The cost of the lens system is also large enough to prevent the cost of the whole camera system from being lowered. The compactness in size, the lightness in weight and the low cost are indispensable for such video camera systems. Therefore, how to construct the lens system as compact in size, light in weight, and low in cost as possible is an important matter.

A solution of the above matter often results in abandoning the use of the zoom lens system and adopting a fixed focal length lens system. Though the adoption of the fixed focal length lens system realizes the compactness in size, the lightness in weight and the low cost of the whole camera system, the charm is much reduced because of the fixed focal length thereof. The focal length of a lens system can be altered by attaching a converter or an attachment thereto. However, such convertor or attachment should be carried separately from the camera body. Additionally, it is hard to be certain that the smaller size, lighter weight and lower cost have been realized, if the converter or attachment is included in the entire system. Also, in recent years, a lens shutter camera including a converter has been proposed so that the converter can be inserted to or retracted from a photographing path to convert the compound focal length of its photographing lens system. However, it is also hard to be certain that such lens shutter camera realizes the smaller size, lighter weight and lower cost. Additionally, since the zoom ratio realized by such lens shutter camera is relatively as small as 2.0 and it is impossible to change the compound focal length with continuing photographing operations, the charm is also much reduced.

Then, a zoom lens system is considered to be applied again. However, most conventional zoom lens systems are designed to achieve a high zoom ratio, and therefore are large in size and very expensive. To the contrary, Japanese Laid-Open Patent Application No. 143311/1986 proposed a zoom lens system designed to realize the compactness in size, light in weight and low in cost with a low zoom ratio, but such a proposed zoom lens system can not be put in practical use because of its insufficient correction of aberrations, particular of the chromatic aberration.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a zoom lens system in which both first and second lens units, counted from the object side, have simple constructions efficiently correcting various aberrations.

The other object of the present invention is to provide a zoom lens system in which the fluctuation of aberrations due to the zooming operation can be decreased and the remaining aberrations can be corrected even if the lens system is set to its shortest focal length condition.

A further object of the present invention is to provide a zoom lens system in which the total length of the zoom lens system is shortened, while maintaining a large aperture ratio and with a small number of lens elements.

A further object of the present invention is to provide a zoom lens system in which the focusing operation is performed by shifting at least a part of the zoom lens group shiftable in the zooming operation so as to be suitable for automatic focusing operation while making the construction of the lens barrel more simple.

The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in conjunction with the accompanying drawings.

To achieve the above-described objects, an aspect of the present invention provides a compact zoom lens system comprising from the object side to the image side: a first lens unit of a positive refractive power, consisting of a negative meniscus lens element having an object side surface convex to the object side, and a bi-convex lens element whose object side surface stronger refractive power than its image side surface has; a second lens unit of a negative refractive power, consisting of a negative lens element whose object side surface has stronger refractive power than its image side surface, and a positive meniscus lens element having an object side surface convex to the object side; and a third lens unit of a negative refractive power; wherein the second lens unit and one of the first and third lens units are shiftable along the optical axis of the lens system in the zooming operation while another thereof is stationary on the optical axis in the zooming operation.

According to another aspect of the present invention, a zoom lens system comprises from the object side to the image side: a first lens unit of a positive refractive power; a second lens unit of a negative refractive power; and a third lens unit of a positive refractive power; wherein one of the first and third lens units is shiftable along the optical axis of the lens system in both the zooming operation and the focusing operation, and the second lens unit is also shiftable along the optical axis of the lens system in the zooming operation.

According to a further aspect of the present invention, a zoom lens system comprises from the object side to the image side: a first lens unit of a positive refractive power, consisting of from the object side to the image side, a negative meniscus lens element having an object side surface convex to the object side, and a bi-convex lens element whose object side surface has stronger refractive power than its image side surface; a second lens unit of a negative refractive power, consisting of a negative lens element whose image side surface has stronger refractive power than its object side surface, and a negative compound lens component in which a negative lens element is cemented a positive lens element; and a third lens unit of a positive refractive power; wherein the second lens unit and one of the first and third lens units are shiftable along the optical axis of the lens system in the zooming operation, while another thereof is stationary on the optical axis in the zooming operation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 represents a cross sectional view of the lens system according to the first and second embodiments of the present invention in the longest focal length condition;

FIG. 2 represents a cross sectional view of the lens system according to the third to eighth embodiments of the present invention in the longest focal length condition;

FIG. 3 represents a cross sectional view of the lens system according to the ninth to fourteenth embodiments of the present invention in the longest focal length condition;

FIG. 4 represents a cross sectional view of the lens system according to the fifteenth embodiment of the present invention in the longest focal length condition;

FIG. 5 represents a cross sectional view of the lens system according to the sixteenth to twenty-first embodiments of the present invention in the longest focal length condition;

FIG. 6 represents a cross sectional view of the lens system according to the twenty-second to twenty-fifth embodiments of the present invention in the longest focal length condition;

FIG. 7 represents a cross sectional view of the lens system according to the twenty-sixth and twenty-seventh embodiments of the present invention in the longest focal length condition;

FIG. 8 represents a cross sectional view of the lens system according to the twenty-sixth embodiment of the present invention in the longest focal length condition;

FIG. 9 represents a cross sectional view of the lens system according to the twenty-ninth to thirty-second embodiments of the present invention in the longest focal length condition;

FIG. 10 represents a cross sectional view of the lens system according to the thirty-third embodiment of the present invention in the longest focal length condition;

FIGS. 11a to 11c represent the aberration curves of the first embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 12a to 12c represent the aberration curves of the first embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 13a to 13c represent the aberration curves of the first embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 14a to 14c represent the aberration curves of the second embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 15a to 15c represent the aberration curves of the second embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 16a to 16c represent the aberration curves of the second embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 17a to 17c represent the aberration curves of the third embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 18a to 18c represent the aberration curves of the third embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 19a to 19c represent the aberration curves of the third embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 20a to 20c represent the aberration curves of the fourth embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 21a to 21c represent the aberration curves of the fourth embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 22a to 22c represent the aberration curves of the fourth embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 23a to 23c represent the aberration curves of the fifth embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 24a to 24c represent the aberration curves of the fifth embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 25a to 25c represent the aberration curves of the fifth embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 26a to 26c represent the aberration curves of the sixth embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 27a to 27c represent the aberration curves of the sixth embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 28a to 28c represent the aberration curves of the sixth embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 29a to 29c represent the aberration curves of the seventh embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 30a to 30c represent the aberration curves of the seventh embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 31a to 31c represent the aberration curves of the seventh embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 32a to 32c represent the aberration curves of the eighth embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 33a to 33c represent the aberration curves of the eighth embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 34a to 34c represent the aberration curves of the eighth embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 35a to 35c represent the aberration curves of the ninth embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 36a to 36c represent the aberration curves of the ninth embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 37a to 37c represent the aberration curves of the ninth embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 38a to 38c represent the aberration curves of the tenth embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 39a to 39c represent the aberration curves of the tenth embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 40a to 40c represent the aberration curves of the tenth embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 41a to 41c represent the aberration curves of the eleventh embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 42a to 42c represent the aberration curves of the eleventh embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 43a to 43c represent the aberration curves of the eleventh embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 44a to 44c represent the aberration curves of the twelfth embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 45a to 45c represent the aberration curves of the twelfth embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 46a to 46c represent the aberration curves of the twelfth embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 47a to 47c represent the aberration curves of the thirteenth embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 48a to 48c represent the aberration curves of the thirteenth embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 49a to 49c represent the aberration curves of the thirteenth embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 50a to 50c represent the aberration curves of the fourteenth embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 51a to 51c represent the aberration curves of the fourteenth embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 52a to 52c represent the aberration curves of the fourteenth embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 53a to 53c represent the aberration curves of the fifteenth embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 54a to 54c represent the aberration curves of the fifteenth embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 55a to 55c represent the aberration curves of the fifteenth embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 56a to 56c represent the aberration curves of the sixteenth embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 57a to 57c represent the aberration curves of the sixteenth embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 58a to 58c represent the aberration curves of the sixteenth embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 59a to 59c represent the aberration curves of the seventeenth embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 60a to 60c represent the aberration curves of the seventeenth embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 61a to 61c represent the aberration curves of the seventeenth embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 62a to 62c represent the aberration curves of the eighteenth embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 63a to 63c represent the aberration curves of the eighteenth embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 64a to 64c represent the aberration curves of the eighteenth embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 65a to 65c represent the aberration curves of the nineteenth embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 66a to 66c represent the aberration curves of the nineteenth embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 67a to 67c represent the aberration curves of the nineteenth embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 68a to 68c represent the aberration curves of the twentieth embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 69a to 69c represent the aberration curves of the twentieth embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 70a to 70c represent the aberration curves of the twentieth embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 71a to 71c represent the aberration curves of the twenty-first embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 72a to 72c represent the aberration curves of the twenty-first embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 73a to 73c represent the aberration curves of the twenty-first embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 74a to 74c represent the aberration curves of the twenty-second embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 75a to 75c represent the aberration curves of the twenty-second embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 76a to 76c represent the aberration curves of the twenty-second embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 77a to 77c represent the aberration curves of the twenty-third embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 78a to 78c represent the aberration curves of the twenty-third embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 79a to 79c represent the aberration curves of the twenty-third embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 80a to 80c represent the aberration curves of the twenty-fourth embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 81a to 81c represent the aberration curves of the twenty-fourth embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 82a to 82c represent the aberration curves of the twenty-fourth embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 83a to 83c represent the aberration curves of the twenty-fifth embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 84a to 84c represent the aberration curves of the twenty-fifth embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 85a to 85c represent the aberration curves of the twenty-fifth embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 86a to 86c represent the aberration curves of the twenty-sixth embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 87a to 87c represent the aberration curves of the twenty-sixth embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 88a to 88c represent the aberration curves of the twenty-sixth embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 89a to 89c represent the aberration curves of the twenty-seventh embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 90a to 90c represent the aberration curves of the twenty-seventh embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 91a to 91c represent the aberration curves of the twenty-seventh embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 92a to 92c represent the aberration curves of the twenty-eighth embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 93a to 93c represent the aberration curves of the twenty-eighth embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 94a to 94c represent the aberration curves of the twenty-eighth embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 95a to 95c represent the aberration curves of the twenty-ninth embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 96a to 96c represent the aberration curves of the twenty-ninth embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 97a 97c represent the aberration curves of the twenty-ninth embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 98a to 98c represent the aberration curves of the thirtieth embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 99a to 99c represent the aberration curves of the thirtieth embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 100a to 100c represent the aberration curves of the thirtieth embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 101a to 101c represent the aberration curves of the thirty-first embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 102a to 102c represent the aberration curves of the thirty-first embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 103a to 103c represent the aberration curves of the thirty-first embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 104a to 104c represent the aberration curves of the thirty-second embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 105a to 105c represent the aberration curves of the thirty-second embodiment for the medium focal length condition in the infinity focusing condition;

FIGS. 106a to 106c represent the aberration curves of the thirty-second embodiment for the shortest focal length condition in the infinity focusing condition;

FIGS. 107a to 107c represent the aberration curves of the thirty-third embodiment for the longest focal length condition in the infinity focusing condition;

FIGS. 108a to 108c represent the aberration curves of the thirty-third embodiment for the medium focal length condition in the infinity focusing condition; and

FIGS. 109a to 109c represent the aberration curves of the twenty-third embodiment for the shortest focal length condition in the infinity focusing condition.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description is provided to enable any person skilled in the commercial camera and video field to make and use the invention and sets forth the best modes contemplated by the inventors for carrying out their invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the generic principles of the present invention have been defined herein specifically to provide a relatively economical and easily manufactured compact zoom lens system. The derivation of the formulas and the relation of the powers set forth herein can be accomplished with the assistance of a computer. The present invention represents the parameters of a compromise balance of acceptable aberrations which can be relatively easily manufactured to provide a low cost lens system for utilization with a video camera or various compact cameras such as a still video camera.

In the drawings, schematic cross sectional views disclose the position of the lens units and lens elements for the longest focal length(T). Especially as to the movable lens units, the movements for zooming toward the shortest focal length(W) are represented by the arrows 1 and 2. In front of a third lens unit (III) explained below, (3) represents a diaphragm, behind the third lens unit (III), (4) represents a flat plate corresponding to a low-pass filter or a face plate. Moreover, in the FIGS. 11a to 109c, a solid line (d) represents an aberration against the d-line, a dotted line (SC) represents a sine condition, a dotted line (DM) represents an astigmatism on the meridional surface and a solid line (DS) represents an astigmatism on the sagittal surface, respectively.

Due to the number of lens elements involved, it was not deemed appropriate to include an individual designation of the radii of curvature and axial distances for each lens element and air space. These values, however, are provided in the accompanying tables set forth herein, and the schematic cross sectional views of the respective embodiments follow the normal conventions of an object at the left-hand side of the drawing and the image plane at the right-hand side.

According to the present invention, a zoom lens system comprises from the object side to the image side: a first lens unit (I) of a positive refractive power, consisting of a negative meniscus lens element having an object side surface convex to the object side, and a bi-convex lens element whose object side surface has stronger refractive power than its image side surface; a second lens unit (II) of a negative refractive power, consisting of a negative lens element whose object side surface has stronger refractive power than its image side surface, and a positive meniscus lens element having an object side surface convex to the object side; and a third lens unit (III) of a negative refractive power; wherein the second lens unit (II) and one of the and third lens units are shiftable along the optical axis of the lens system in the zooming operation while another thereof is stationary on the optical axis in the zooming operation.

In the present invention, negative lens elements are located at the object side in both of the first lens unit (I) and the second lens unit (II) respectively for decreasing incident angles of paraxial light rays on the respective following lens elements. It is effective for controlling the generation of the coma aberration and the field curvature in the paraxial region, and also for compensating the spherical aberration in the axial region. Additionally, since both the first and second lens units consist of a combination of one positive lens element and one negative lens element respectively, the fluctuation of the lateral chromatic aberration and that of the longitudinal chromatic aberration in the zooming operation can be corrected. The first and second lens units may consist of a compound lens component in which one positive lens element and one negative lens element are cemented with each other for making its manufacture simple, respectively. However, it is desirable for correcting the aberrations that the first and second lens units consist of a separated lens component in which one positive lens element and one negative lens element are separated from each other.

According to one type of above mentioned zoom lens system, in which the first lens unit (I) is shiftable along the optical axis in the zooming operation while the third lens unit (III) is stationary on the optical axis to converge the divergent light projected through the second lens unit (II), a high optical performance of the whole lens system can be obtained, although the zooming part shiftable in the zooming operation is composed of only four lens elements.

On the other hand, another type of zoom lens system, in which the first lens unit (I) is stationary on the optical axis while the third lens unit (III) is shiftable along the optical axis, corresponding to a shift of the second lens unit(II) is effective for preventing a radius of the front lens element from being long.

Moreover, maintaining the aberration compensated condition in the zooming operation, the lens system is required to fulfill the following conditions:

0.05<R.sub.1P /R.sub.2R <0.43(R.sub.2R <0) (1) 0.30<R.sub.4R /R.sub.1P <0.60 (2) 0.28<.phi..sub.I /.vertline..phi..sub.II .vertline.<0.45(.phi..sub.II <0)(3) 0.38<R.sub.3R .multidot..vertline..phi..sub.II .vertline.<0.75(.phi..sub.II <0) (4) 0.65<R.sub.1R /R.sub.2P <1.00 (5) (n.sub.1 +n.sub.4)/2>1.78 (6) wherein; R represents the radius of curvature, wherein the first subscript thereof represents the lens number counted from the object side, and the second subscript thereof, that is P represents the object side surface and R represents the image side surface; .phi..sub.I represents the refractive power of the first lens unit; .phi..sub.II represents the refractive power of the second lens unit; and n.sub.i represents the refractive index of the i-th lens element counted from the object side.

The above described condition (1) defines, regarding the whole first lens unit as a single positive lens element, the ratio of the refractive power of the object side surface to that of the image side surface, and greatly affects the aberrations in the marginal region. If the lower limit of the condition (1) is violated, the coma aberration in the upper region is undesirably generated by the outer ray passing outside the principal ray of the marginal ray especially in the longest focal length condition. To the contrary, if the upper limit of the condition (1) is violated, the coma aberration in the upper region is undesirably generated. Thus, a good performance for correcting aberrations cannot be secured while violating the condition (1).

Condition (2) defines the meniscus shape, regarding the first lens unit (I) and the second lens unit (II) as one single negative meniscus lens element as a whole. As in the condition (1), the condition (2) greatly influences on the coma aberration and the spherical aberration in the longest focal length condition. If the lower limit of the condition (2) is violated, the upper comatic aberration increases and the spherical becomes in under-corrected condition. On the other hand, if the upper limit of the condition (2) is violated, the lower comatic aberration increases and the spherical aberration becomes over-corrected. That is, a good performance for correcting the aberrations cannot be secured without fulfilling condition (2).

Condition (3) defines the ratio of refractive power of the first lens unit (I) to that of the second lens unit (II). If the lower limit of the condition (3) is violated, the optical performance is deteriorated greatly because of a higher degree of aberration generated by the second lens unit (II), although it is possible to make the lens system compact. On the other hand, if the upper limit of the condition (3) is violated, it is required to extend the diameter of the front lens unit for maintaining the sufficient quantity of marginal light. Therefore, the compactness in size and the lightness in weight cannot be satisfied, and the Petzval sum becomes large to deteriorate the field curvature.

Condition (4) defines the refractive power of the strongest refractive surface of the negative lens element in the second lens unit (II), and especially affects the spherical aberration and the field curvature in the longest focal length condition. The spherical aberration and the field curvature become over-corrected if the lower limit of the condition (4) is violated, and become under-corrected if the upper limit of the condition (4) is violated, so that the sufficient optical performance cannot be obtained without fulfilling the condition (4).

Condition (5) defines the ratio of radii of curvature of two surfaces being each other within the first lens unit (I). If the negative lens element and the positive lens element in the first lens unit (I) are cemented to each other, the above parameter becomes 1.0. To the contrary, if the negative lens element is spaced from the positive lens element, the radius of curvature of the surface of the negative lens element is required to be smaller than that of the positive lens element side. If the upper limit of the condition (5) is violated, that is, the radius of curvature of the surface of the negative lens element side is larger than that of the positive lens element side, negative distortion becomes too large. On the other hand, it is unfavorable that the lower limit of the condition (5) is violated, that is, the radius of curvature of the surface of the negative lens element side becomes too small resulting in too much generation of lower chromatic aberration in the longest focal length condition.

Condition (6) shows that the negative lens element of the first lens unit (I) and the positive lens element of the second lens unit (II) should be made of glass materials having a sufficiently high refractive indice, respectively. In case the condition (6) is not satisfied, the generation of high degree aberrations cannot be compensated.

Provided the above mentioned conditions are fulfilled, the compactness of the whole lens system, the lightness thereof and low cost thereof are improved while controlling the fluctuation of aberrations in the zooming operation and while compensating the remaining aberrations even in the shortest focal length condition.

Furthermore, a low cost zoom lens system having a good aberration correction can be obtained by the third lens unit (III), in addition to the above mentioned zooming part consisting of the first lens unit (I) and the second lens unit (II).

That is, the third lens unit (III) consists of, from the object side to the image side, a positive lens element whose object side surface has stronger refractive power than its image side surface, a bi-concave lens element, a positive lens element whose image side surface has stronger refractive power than its object side surface, and a positive lens element whose object side surface has stronger refractive power than its image side surface. This construction of the third lens unit (III) makes it possible to secure a compact zoom lens system having a sufficient back focal distance while making the correction of the various aberrations easy.

Moreover, a good performance can be also obtained by fulfilling the following conditions:

1.0<A.sub.1 /A.sub.2 (7) 0.40<.vertline.R.sub.6P .vertline./R.sub.6R <1.20(R.sub.6P <0)(8) (9) 0.60<f.sub.7 .multidot..phi..sub.7R <1.30(wherein .phi..sub.7R =(n.sub.7 -1)/.vertline.R.sub.7R .vertline.) (9) 0.70<f.sub.8 .multidot..phi..sub.8P <1.60(wherein .phi..sub.8P =(n.sub.8 -1)/R.sub.8P) (10) wherein; A.sub.1 represents the axial air space between the fifth lens element and the sixth lens element counted from the object side; A.sub.2 represents the axial air space between the sixth lens element and the seventh lens element counted from the object side; and f.sub.i represents the focal length of the i-th lens element counted from the object side.

Condition (7) defines the axial air spaces in front of and behind the sixth lens element which is the only negative lens element in the third lens unit (III) in which the air space on the object side is larger than that on the image side. The distribution and the lateral chromatic aberration are greatly influenced by the arrangement of the sixth lens element. If the lower limit of the condition (7) is violated, the negative distortion is greatly generated, and the lateral chromatic aberration is too large to be corrected.

Condition (8) defines the distribution of power between the object side surface and the rear side surface of the negative sixth lens element. The sixth lens element, which is the only negative lens element in the third lens unit (III), is so important as to cancel the various aberrations caused by the other three lens elements in the third lens unit (III). If the refractive power is concentrated on the object side surface of the sixth lens element while violating the lower limit of the condition (8), the negative distortion is undesirably generated and the field curvature is also deteriorated. To the contrary, if the refractive power is concentrated on the image side surface of the sixth lens element while violating the upper limit of the condition (8), the deterioration in the optical performance is caused by the over generation of sagittal flare and aberration of higher degrees and it becomes difficult to maintain a sufficient back focal distance.

Condition (9) defines that the positive refractive power of the seventh lens element should be concentrated on the image side surface thereof, while condition (10) defines that the positive refractive power of the eighth lens element should be concentrated on the object side surface thereof. On each of these conditions (9) and (10), if the parameter in each of the conditions becomes smaller than 1.0, the lens element becomes a bi-convex lens element. On the other hand, if the parameter in each of the conditions becomes larger than 1.0, the lens element becomes a meniscus lens element. The most suitable shape for the both lens elements is determined in accordance with the balance among the spherical aberration, the field curvature in off-axial region, the distortion, and the coma aberration. If the lower limit of each of the conditions (9) and (10) is violated, the aberrations in the off-axial region is deteriorated although it is favorable to correct the spherical aberration. To the contrary, if the upper limit of each of the conditions (9) and (10) is violated, the spherical aberration and the distortion in the off-axial region are deteriorated.

Provided the third lens unit (III) is composed while fulfilling the above mentioned conditions, a compact-size, light-weight, and low-cost zoom lens system having a large aperture ratio and high optical performance can be realized by only eight lens elements.

As a second type of the third lens unit (III), the third lens unit (III) is capable of consisting of, from the object side to the image side, a positive lens element whose image side surface has stronger refractive power than its object side surface, a positive lens element whose object side surface has stronger refractive power than its image side surface, a bi-concave lens element whose image side surface has stronger refractive power than its object side surface, and a bi-convex lens element. According to the second type of the third lens unit (III), it is possible to make the third lens unit (III) very compact. Additionally, the negative refractive power is located comparatively at the image side of the whole lens system, the Petzval sum can be enough small and a good forming performance can be obtained.

Further, the third lens unit (III) with a very good optical performance can be obtained by fulfilling the following conditions:

0.30<f.sub.6 /f.sub.5 <0.60 (11) 0.10<R.sub.7R /.vertline.R.sub.7P .vertline.<0.50(R.sub.7P <0)(12) 0.20<T.sub.7 /f.sub.W <0.60 (13) wherein: T.sub.7 represents the axial thickness of the seventh lens element counted from the object side; and f.sub.W represents the shortest focal length of the whole lens system.

Condition (11) defines a balance of refractive powers between the two lens elements preceding in the third lens unit (III). If the refractive power of the fifth lens element becomes weak while violating the lower limit of condition (11), the positive refractive power of the sixth lens element and that of the eighth lens element should be made stronger to deteriorate the spherical aberration. On the other hand, if the upper limit of condition (11) is violated, it becomes difficult to obtain a sufficient back focal distance, so the lens system could not be put to a practical use.

Condition (12) refers to the balance of the refractive powers of the object side surface of the seventh lens element and the image side surface thereof. If the refractive power of the image side surface becomes stronger while violating the lower limit of condition (12), the chromatic aberration of the high degree is much generated. To the contrary, if the refractive power of the object side surface becomes stronger while violating the upper limit of condition (12), it would result in the over-correction of the spherical aberration and the generation of negative distortion.

Condition (13) defines the axial thickness of the seventh lens element. For correcting the off-axial aberration and the field curvature, a greater axial thickness of the seventh lens element is desirable. If the thickness of the seventh lens element becomes smaller while violating the lower limit of condition (13), the off-axial aberration and the field curvature would not be corrected. If the thickness of the seventh lens element becomes larger while violating the upper limit of condition (13), a sufficient back focal distance could not be obtained though the optical performance of the lens system would be improved, so that the lens system could not be put to a practical use.

Provided the third lens unit (III) is composed fulfilling the above mentioned conditions (11) to (13), to some extent the aberrations would be corrected.

In the present invention, it is desirable that the focusing operation of the zoom lens system is performed by shifting one of the first lens unit (I) and the third lens unit (III) which is shiftable in the zooming operation. The above mentioned structure would have good results as follows.

Recently, an automatic focusing device is indispensable for a video camera system or other camera system, and therefore many kinds of automatic focusing devices are suggested and utilized. If such an automatic focusing device, in which the focusing condition of the lens system is detected by receiving light passed through the lens system, is adapted to the zoom lens system according to the present invention, a cam mechanism, provided for shifting the focusing lens unit in relation to the shifting the second lens unit (II) during the zooming operation, can be omitted.

That is, according to the present invention, the focusing lens unit (consisting of either of the first lens unit (I) and the third lens unit (III)) is shifted for the focusing of the whole lens system in the focusing operation and also for maintaining the image plane at a predetermined plane as a compensator lens unit in the zooming operation. In other words, the operation of a compensator in the zoom lens system can be regarded as one of the focusing operations. The lens elements and the lens-barrel can not be separated in considering the cost, size and weight of the zoom lens system. As for the lens-barrel of the zoom lens system, the shifting mechanism such as a cam mechanism or a helicoid mechanism requiring a high definition large in cost and in weight in the whole lens-barrel body, so omitting the cam mechanism and the helicoid mechanism is a great advantage of the above identified process through the lens automatic focusing operation. Moreover, according to the present invention, as only two lens units are shiftable during the zooming or the focusing operations, the deterioration of optical performance by unsteadiness of the shiftable lens units can be relaxed.

In the present invention, the zoom lens system in which the third lens unit (III) thereof is left stationary during the zooming operation and the first lens unit (I) thereof serves as a focusing lens unit, will be materialized effectively provided the following conditions are fulfilled:

0.28<.phi..sub.I /.vertline..phi..sub.II .vertline.<0.43(.phi..sub.II <0)(14) 0.18<.phi..sub.I .multidot.f.sub.W <0.32 (15)

Condition (14) defines the ratio of the refractive powers between the first lens unit (I) and the second lens unit (II). A curve and amount of movement of the first lens unit (I) in the zooming operation are affected by the above mentioned ratio. If the ratio becomes small while violating the lower limit of condition (14), the first lens unit (I) would deviate to the object side in the longest focal length condition in comparison with the shortest focal length condition and a sufficient quantity of marginal ray could not be secured in the longest focal length condition. Also, if the ratio becomes large while violating the upper limit of condition (14), the first lens unit (I) would deviate to the object side in the shortest focal length condition, and a sufficient quantity of marginal ray could not be secured in the shortest focal length condition. Both of the above cases make the first lens unit (I) larger, which is large in weight. Moreover, if the above mentioned ratio is outside of the limits of condition (14), it would be inconvenient for correcting various aberrations in the zooming operation.

Condition (15) defines the refractive power of the first lens unit (I). If the lower limit of condition (15) is violated, the first lens unit (I) would become larger in size, therefore the lightness in weight and the compactness in size thereof could not be achieved. On the other hand, violating the upper limit of condition (15) would be advantageous to the compactness in size, but a sufficient back focal distance could not be secured. In addition too much aberration of higher degrees would arise preventing simplification of the structure of the whole lens system and lowering costs.

Further, without adapting the TTL automatic focusing operation, an effect that the shifting distance is invariable in any focal length condition could be expected provided the first lens unit (I) serves as a focusing lens unit.

Meanwhile, if the first lens unit (I) is left stationary during the zooming operation and the third lens unit (III) serves as a focusing lens unit, the following effects could be expected.

That is, the first positive lens unit (I) doesn't need to shift during the focusing operation, and so a sufficient quantity of marginal ray is secured even in a close-up condition. Therefore the diameter of the front lens element becomes quite short in comparison with the case that the first lens unit (I) serves as a focusing lens unit. The lightness in weight owing to a small diameter of the front lens element is very advantageous, because the front lens element possesses the majority of the weight of the whole lens system utilized for a video camera or a compact camera.

Moreover, the third lens unit (III) can possess quite strong refractive power compared with the first lens unit (I), and so the shifting distance of the third lens unit (III) as a compensator as well as the shifting distance of the third lens unit (III) for the focusing operation can be quite shorter in comparison with the case that the first lens unit (I) serves as a focusing lens unit. So far as the short shifting distance, a relatively distinct picture image is secured even during the focusing operation, due to a low variable power rate and a focal length range in the shortest focal length side. Therefore the zoom lens system with low cost and simple structure can be utilized.

In accordance with the present invention, the lens system is further recommended to fulfill the following conditions:

0.28 <.phi..sub.I /.vertline..phi..sub.II .vertline.>0.43(.phi..sub.II <0)(16) 0.85<.phi..sub.III .multidot.f.sub.W <1.70(wherein f.sub.M =(f.sub.W .multidot.f.sub.T).sup.1/2) (17) wherein: .phi..sub.III represents the refractive power of the third lens unit; and f.sub.T represents the longest focal length of the whole lens system.

Condition (16) defines the ratio of the refractive powers between the first lens unit (I) and the second lens unit (II). A curve and an amount of movement of the third lens unit (III) as a compensator are affected by the above mentioned ratio. If the ratio becomes smaller while violating the lower limit of condition (16), the third lens unit (III) would deviate to the image side in the shortest focal length condition in comparison while in the longest focal length condition, and the cam mechanism could not be omitted. In addition a sufficient quantity of marginal ray could not be secured in the longest focal length condition. Also, if the ratio becomes larger while violating the upper limit of condition (16), the third lens unit (III) would deviate to the image side in the longest focal length condition, and a sufficient quantity of marginal ray could not be secured in the longest focal length condition.

Condition (17) defines the refractive power of the third lens unit (III). If the lower limit of condition (17) is violated, the third lens unit (III) would shift too much during the focusing operation. On the other hand, if the upper limit of condition (17) is violated, the shifting distance of the third lens unit (III) would become smaller, but a sufficient back focal distance could not be secured.

Provided that the above mentioned conditions (16) and (17) on the focusing operation, a concrete structure of the first, second and third lens units (I), (II) and (III) can adapt the above mentioned structure of the zoom lens system. But the extent of conditions (1), (3) and (5) are further recommended to be the following conditions:

0.05<R.sub.1P /.vertline.R.sub.2R .vertline.<0.45(R.sub.2R <0)(1)' 0.43<R.sub.3R .multidot..vertline..phi..sub.II .vertline.<0.75(.phi..sub.II <0) (3)' 0.60<R.sub.1R /R.sub.2P <1.00 (5)'

In the present invention, the second lens unit (II) of the above mentioned zoom lens system can comprise three lens elements, that is, from the object side to the image side, a negative lens element whose image side surface having a stronger refractive power than its object side surface, a negative lens component in which a negative lens element and a positive lens element are cemented to each other. The above construction is for securing enough optical performance even in the shortest focal length condition as well as moderately reducing the fluctuation of the aberrations during the zooming operation. In this case, the lens system is recommended to further fulfill the following conditions:

0<R.sub.1P /.vertline.R.sub.2R .vertline.<0.5(R.sub.2R <0) (1)" 0.27<.phi..sub.I /.vertline..phi..sub.II .vertline.<0.40(.phi..sub.II <0)(3)" 1.0<A.sub.1 /A.sub.2 (7)" 0.40<.vertline.R".sub.7P .vertline./R".sub.7R <1.20(R.sub.7P <0)(8)" 0.30<f".sub.7 /f".sub.6 <0.6 (11)" 0.05<R".sub.8R /R".sub.8P <0.5(R.sub.8P <0) (12)" 0.18<.phi..sub.I .multidot.f.sub.W <0.35 (15)" 0.85<.phi..sub.III .multidot.f.sub.M <1.70 (17)" wherein; R".sub.7P and R".sub.7R in the condition (8)" represent R.sub.6P and R.sub.6R in the condition (8), respectively; R".sub.8P and R".sub.8R in the condition (12)" represent R.sub.7P and R.sub.7R in the condition (12), respectively; and f".sub.7 and f".sub.6 in the condition (11) represent f.sub.6 and f.sub.5 in the condition (11) respectively. The respective conditions are similar in the problems caused by the violating the upper or the lower limit thereof to the condition (1), (3), (7), (8), (11), (12), (15) and (17).

Condition (15)" is effective based on the construction of the zoom lens system in which the first and the second lens units (I) and (II) are movable during the zooming operation, while the third lens unit (III) is left stationary. On the other hand, condition (17)" is effective based on the construction of the zoom lens system in which the first lens unit (I) is left stationary, while the second and the third lens units (II) and (III) are movable during the zooming operation.

Moreover, condition (7)" and (8)" are effective, provided that the third lens unit (III) is composed of four lens elements, from the object side to the image side, a positive lens element whose object side surface has a stronger refractive power than its image side surface, a bi-concave lens, a positive lens element whose image side surface has a stronger refractive power than its object side surface, and a positive lens element whose object side surface has a stronger refractive power than its image side surface.

Meanwhile, condition (11)" and (12)" are effective, provided that the third lens unit (III) is composed of four lens elements, from the object side to the image side, a positive lens element whose image side surface has a stronger refractive power than its object side surface, a positive lens element whose object side surface has a stronger refractive power than its image side surface, a bi-concave lens whose image side surface has a stronger refractive power than its object side surface, and a bi-convex lens.

The following Tables 1 to 33 disclose, respectively, the first to thirty-third embodiments of the present invention. In the Tables, f equals the focal length; r is radius of curvature with respective sub number indicating the surfaces from the object side to the image side along the optical axis; d represents the axial distance and includes both the air spaces and the actual thickness of the lens elements along the optical axis; Nd equals the refractive index and again, the sub numbers refer to the particular optical element from the object side to the image side; and finally, d equals the Abbe number and the sub numbers refer to the particular optical elements from the object side to the image side. In the first to thirty-third embodiments of the present invention, respectively, a flat board corresponding to a low-pass filter or a face plate is inserted at the end of the each embodiment. The air space distances in the Tables provided with three separate values correspond to the values for the shortest, medium and longest focal length conditions, respectively.

TABLE 1______________________________________Embodiment 1f = 25.0-12.3 F = 1.63--1.63Radius of Axial Refracive AbbeCurvature Distance Index (Nd) Number (.nu.d)______________________________________r.sub.1 39.064 d.sub.1 1.200 N.sub.1 1.80518 .nu..sub.1 25.43r.sub.2 23.030 d.sub.2 4.100 N.sub.2 1.69100 .nu..sub.2 54.75r.sub.3 -199.877 d.sub.3 14.635 N.sub.3 1.00000r.sub.4 -51.773 d.sub.4 1.000 N.sub.4 1.69350 .nu..sub.4 50.29r.sub.5 8.957 d.sub.5 3.200 N.sub.5 1.80518 .nu..sub.5 25.43r.sub.6 16.871 d.sub.6 3.000 N.sub.6 1.00000r.sub.7 .infin. d.sub.7 1.500 N.sub.7 1.00000r.sub.8 14.100 d.sub.8 3.100 N.sub.8 1.71300 .nu..sub.8 53.93r.sub.9 -42.404 d.sub.9 2.624 N.sub.9 1.00000r.sub.10 -13.251 d.sub.10 4.931 N.sub.10 1.75520 .nu..sub.10 27.51r.sub.11 17.883 d.sub.11 1.611 N.sub.11 1.00000r.sub.12 65.100 d.sub.12 4.466 N.sub.12 1.67000 .nu..sub.12 57.07r.sub.13 -14.473 d.sub.13 0.100 N.sub.13 1.00000r.sub.14 18.071 d.sub.14 4.001 N.sub.14 1.67000 .nu..sub.14 57.07r.sub.15 -112.445 d.sub.15 2.000 N.sub.15 1.00000r.sub.16 .infin. d.sub.16 3.000 N.sub.16 1.51680 .nu..sub.16 64.12r.sub.17 .infin.d.sub.3 = 14.635-8.649-1.500d.sub.6 = 3.000-13.476-19.631______________________________________ TABLE 2______________________________________Embodiment 2f = 17.8-9.2 F = 1.63--1.63Radius of Axial Refractive AbbeCurvature Distance Index (Nd) Number (.nu.d)______________________________________r.sub.1 28.571 d.sub.1 1.300 N.sub.1 1.80518 .nu..sub.1 25.43r.sub.2 18.510 d.sub.2 1.200 N.sub.2 1.00000r.sub.3 21.945 d.sub.3 4.600 N.sub.3 1.77250 .nu..sub.3 49.77r.sub.4 -131.591 d.sub.4 10.929 N.sub.4 1.00000r.sub.5 -398.359 d.sub.5 1.000 N.sub.5 1.77250 .nu..sub.5 49.77r.sub.6 8.312 d.sub.6 1.700 N.sub.6 1.00000r.sub.7 8.645 d.sub.7 2.400 N.sub.7 1.80518 .nu..sub.7 25.43r.sub.8 10.669 d.sub.8 2.800 N.sub.8 1.00000r.sub.9 .infin. d.sub.9 1.500 N.sub.9 1.00000r.sub.10 9.525 d.sub.10 3.200 N.sub.10 1.77250 .nu..sub.10 49.77r.sub.11 -44.793 d.sub.11 2.200 N.sub.11 1.00000r.sub.12 - 10.396 d.sub.12 3.400 N.sub.12 1.80518 .nu..sub.12 25.43r.sub.13 11.678 d.sub.13 0.800 N.sub.13 1.00000r.sub.14 83.678 d.sub.14 3.500 N.sub.14 1.77250 .nu..sub.14 49.77r.sub.15 -10.533 d.sub.15 0.100 N.sub.15 1.00000r.sub.16 9.889 d.sub.16 3.600 N.sub.16 1.77250 .nu..sub.16 49.77r.sub.17 28.070 d.sub.17 2.000 N.sub.17 1.00000r.sub.18 .infin. d.sub.18 8.600 N.sub.18 1.51680 .nu..sub.18 64.12r.sub.19 .infin.d4 = 10.929-6.054-1.500 d8 = 2.800-8.862-11.788______________________________________ TABLE 3______________________________________Embodiment 3f = 17.8-9.2 F = 1.63--1.63Radius of Axial Refracive AbbeCurvature Distance Index (Nd) Number (.nu.d)______________________________________r.sub.1 26.466 d.sub.1 1.300 N.sub.1 1.84666 .nu..sub.1 23.83r.sub.2 18.584 d.sub.2 1.200 N.sub.2 1.00000r.sub.3 22.040 d.sub.3 4.600 N.sub.3 1.77250 .nu..sub.3 49.77r.sub.4 -203.157 d.sub.4 10.688 N.sub.4 1.00000r.sub.5 440.748 d.sub.5 1.000 N.sub.5 1.77250 .nu..sub.5 49.77r.sub.6 8.122 d.sub.6 1.700 N.sub.6 1.00000r.sub.7 8.415 d.sub.7 2.400 N.sub.7 1.84666 .nu..sub.7 23.8r.sub.8 9.922 d.sub.8 2.800 N.sub.8 1.00000r.sub.9 .infin. d.sub.9 1.500 N.sub.9 1.00000r.sub.10 9.298 d.sub.10 3.200 N.sub.10 1.77250 .nu..sub.10 49.77r.sub.11 -44.119 d.sub.11 2.200 N.sub.11 1.00000r.sub.12 -10.315 d.sub. 12 3.400 N.sub.12 1.84666 .nu..sub.12 23.8r.sub.13 11.873 d.sub.13 0.800 N.sub.13 1.00000r.sub.14 91.680 d.sub.14 3.500 N.sub.14 1.77250 .nu..sub.14 49.77r.sub.15 -10.432 d.sub.15 0.100 N.sub.15 1.00000r.sub.16 10.076 d.sub.16 3.600 N.sub.16 1.77250 .nu..sub.16 49.77r.sub.17 36.475 d.sub.17 2.000 N.sub.17 1.00000r.sub.18 .infin. d.sub.18 8.600 N.sub.18 1.51680 .nu..sub.18 64.12r.sub.19 .infin.d4 = 10.688-5.679-1.000 d8 = 2.800-8.700-11.548______________________________________ TABLE 4______________________________________Embodiment 4f = 17.8-7.2 F = 1.63Radius of Axial Refractive AbbeCurvature Distance Index (Nd) Number (.nu.d)______________________________________r.sub.1 25.958 d.sub.1 1.300 N.sub.1 1.84666 .nu..sub.1 23.8r.sub.2 17.704 d.sub.2 1.200 N.sub.2 1.00000r.sub.3 21.399 d.sub.3 5.100 N.sub.3 1.71300 .nu..sub.3 53.93r.sub.4 -111.598 d.sub.4 10.380 N.sub.4 1.00000r.sub.5 -760.919 d.sub.5 1.000 N.sub.5 1.71300 .nu..sub.5 53.93r.sub.6 8.274 d.sub.6 1.700 N.sub.6 1.00000r.sub.7 8.643 d.sub.7 2.400 N.sub.7 1.84666 .nu..sub.7 23.8r.sub.8 10.570 d.sub.8 2.800 N.sub.8 1.00000r.sub.9 .infin. d.sub.9 1.500 N.sub.9 1.00000r.sub.10 9.740 d.sub.10 3.200 N.sub.10 1.77250 .nu..sub.10 49.77r.sub.11 -37.466 d.sub.11 2.100 N.sub.11 1.00000r.sub.12 -10.765 d.sub.12 3.200 N.sub.12 1.84666 .nu..sub.12 23.8r.sub.13 12.107 d.sub.13 0.800 N.sub.13 1.00000r.sub.14 233.851 d.sub.14 3.500 N.sub.14 1.77250 .nu..sub.14 49.77r.sub.15 -10.402 d.sub.15 0.100 N.sub.15 1.00000r.sub.16 10.030 d.sub.16 3.600 N.sub.16 1.77250 .nu..sub.16 49.77r.sub.17 32.993 d.sub.17 2.000 N.sub.17 1.00000r.sub.18 .infin. d.sub.18 8.600 N.sub.18 1.51680 .nu..sub.18 64.12r.sub.19 .infin.d4 = 10.380-5.530-1.000 d8 = 2.800-10.728-14.555______________________________________ TABLE 5______________________________________Embodiment 5f = 19.8-10.2 F = 1.63--1.63Radius of Axial Refractive AbbeCurvature Distance Index (Nd) Number (.nu.d)______________________________________r.sub.1 25.257 d.sub.1 1.300 N.sub.1 1.84666 .nu..sub.1 23.8r.sub.2 17.622 d.sub.2 1.200 N.sub.2 1.00000r.sub.3 22.411 d.sub.3 4.000 N.sub.3 1.71300 .nu..sub.3 53.93r.sub.4 -93.886 d.sub.4 10.986 N.sub.4 1.00000r.sub.5 -92.158 d.sub.5 1.000 N.sub.5 1.71300 .nu..sub.5 53.93r.sub.6 8.784 d.sub.6 1.700 N.sub.6 1.00000r.sub.7 8.968 d.sub.7 2.300 N.sub.7 1.84666 .nu..sub.7 23.8r.sub.8 10.778 d.sub.8 2.900 N.sub.8 1.00000r.sub.9 .infin. d.sub.9 1.500 N.sub.9 1.00000r.sub.10 9.969 d.sub.10 3.500 N.sub.10 1.78831 .nu..sub.10 47.32r.sub.11 -40.726 d.sub.11 2.200 N.sub.11 1.00000r.sub.12 -11.211 d.sub.12 3.400 N.sub.12 1.84666 .nu..sub.12 23.8r.sub.13 12.178 d.sub.13 0.800 N.sub.13 1.00000r.sub.14 88.258 d.sub.14 3.200 N.sub.14 1.78831 .nu..sub.14 47.32r.sub.15 -11.860 d.sub.15 0.100 N.sub.15 1.00000r.sub.16 11.261 d.sub.16 3.100 N.sub.16 1.78831 .nu..sub.16 23.8r.sub.17 38.959 d.sub.17 2.000 N.sub.17 1.00000r.sub.18 .infin. d.sub.18 8.600 N.sub.18 1.51680 .nu..sub.18 64.12r.sub.19 .infin.d.sub.4 = 10.986-6.035-1.000 d.sub.8 = 2.900-9.199-12.498______________________________________ TABLE 6______________________________________Embodiment 6f = 24.6-10.25 F = 1.63--1.63Radius of Axial Refractive AbbeCurvature Distance Index (Nd) Number (.nu.d)______________________________________r.sub.1 28.367 d.sub.1 1.300 N.sub.1 1.84666 .nu..sub.1 23.8r.sub.2 18.677 d.sub.2 1.200 N.sub.2 1.00000r.sub.3 21.798 d.sub.3 4.600 N.sub.3 1.71300 .nu..sub.3 53.93r.sub.4 -103.356 d.sub.4 13.504 N.sub.4 1.00000r.sub.5 -67.611 d.sub.5 1.000 N.sub.5 1.71300 .nu..sub.5 53.93r.sub.6 9.766 d.sub.6 1.700 N.sub.6 1.00000r.sub.7 9.581 d.sub.7 2.300 N.sub.7 1.84666 .nu..sub.7 23.8r.sub.8 11.184 d.sub.8 3.200 N.sub.8 1.00000r.sub.9 .infin. d.sub.9 1.500 N.sub.9 1.00000r.sub.10 10.900 d.sub.10 3.500 N.sub.10 1.78831 .nu..sub.10 47.32r.sub.11 -53.032 d.sub.11 2.900 N.sub.11 1.00000r.sub.12 -11.953 d.sub.12 4.300 N.sub.12 1.84666 .nu..sub.12 23.8r.sub.13 13.464 d.sub.13 0.800 N.sub.13 1.00000r.sub.14 64.746 d.sub.14 3.100 N.sub.14 1.78831 .nu..sub.14 47.32r.sub.15 -13.641 d.sub.15 0.100 N.sub.15 1.00000r.sub.16 12.387 d.sub.16 3.000 N.sub.16 1.78831 .nu..sub.16 47.32r.sub.17 52.570 d.sub.17 2.000 N.sub.17 1.00000r.sub.18 .infin. d.sub.18 8.600 N.sub.18 1.51680 .nu..sub.18 61.12r.sub.19 .infin.d4 = 13.504-6.742-1.000 d8 = 3.200-13.695-17.408______________________________________ TABLE 7______________________________________Embodiment 7f = 19.7-10.2 F = 1.44--1.44Radius of Axial Refractive AbbeCurvature Distance Index (Nd) Number (.nu.d)______________________________________r.sub.1 27.778 d.sub.1 1.400 N.sub.1 1.84666 .nu..sub.1 23.8r.sub.2 18.868 d.sub.2 1.200 N.sub.2 1.00000r.sub.3 22.955 d.sub.3 4.200 N.sub.3 1.71300 .nu..sub.3 53.93r.sub.4 -100.876 d.sub.4 11.414 N.sub.4 1.00000r.sub.5 -82.740 d.sub.5 1.000 N.sub.5 1.71300 .nu..sub.5 53.93r.sub.6 9.729 d.sub.6 1.700 N.sub.6 1.00000r.sub.7 9.737 d.sub.7 2.500 N.sub.7 1.84666 .nu..sub.7 23.8r.sub.8 11.429 d.sub.8 3.100 N.sub.8 1.00000r.sub.9 .infin. d.sub.9 1.500 N.sub.9 1.00000r.sub.10 10.873 d.sub.10 3.900 N.sub.10 1.78831 .nu..sub.10 47.32r.sub.11 -35.301 d.sub.11 2.600 N.sub.11 1.00000r.sub.12 -10.552 d.sub.12 4.700 N.sub.12 1.84666 .nu..sub.12 23.8r.sub.13 14.410 d.sub.13 0.900 N.sub.13 1.00000r.sub.14 106.550 d.sub.14 3.300 N.sub.14 1.77250 .nu..sub.14 49.77r.sub.15 -12.358 d.sub.15 0.100 N.sub.15 1.00000r.sub.16 12.235 d.sub.16 3.900 N.sub.16 1.77250 .nu..sub.16 49.77r.sub.17 123.957 d.sub.17 2.000 N.sub.17 1.00000r.sub.18 .infin. d.sub.18 8.600 N.sub.18 1.51680 .nu..sub.18 64.12r.sub.19 .infin.d.sub.4 = 11.414-6.279-1.000 d.sub.8 = 3.100-9.601-13.062______________________________________ TABLE 8______________________________________Embodiment 8f = 21.7-11.2 F = l.72-1.44Radius of Axial Refractive AbbeCurvature Distance Index (Nd) Number (.nu.d)______________________________________r.sub.1 27.778 d.sub.1 1.400 N.sub.1 1.84666 .nu..sub.1 23.8r.sub.2 19.455 d.sub.2 1.500 N.sub.2 1.00000r.sub.3 25.369 d.sub.3 3.800 N.sub.3 1.69680 .nu..sub.3 56.47r.sub.4 -92.901 d.sub.4 2.879 N.sub.4 1.00000r.sub.5 -69.237 d.sub.5 1.100 N.sub.5 1.69680 .nu..sub.5 56.47r.sub.6 10.184 d.sub.6 1.900 N.sub.6 1.00000r.sub.7 10.012 d.sub.7 2.300 N.sub.7 1.84666 .nu..sub.7 23.8r.sub.8 11.660 d.sub.8 3.300 N.sub.8 1.00000r.sub.9 .infin. d.sub.9 1.500 N.sub.9 1.00000r.sub.10 11.651 d.sub.10 4.300 N.sub.10 1.77250 .nu..sub.10 49.77r.sub.11 -34.395 d.sub.11 3.200 N.sub.11 1.00000r.sub.12 - 10.200 d.sub.12 6.500 N.sub.12 1.84666 .nu..sub.12 23.8r.sub.13 16.579 d.sub.13 0.800 N.sub.13 1.00000r.sub.14 86.928 d.sub.14 3.300 N.sub.14 1.77250 .nu..sub.14 49.77r.sub.15 -13.784 d.sub.15 0.100 N.sub.15 1.00000r.sub.16 12.794 d.sub.16 3.900 N.sub.16 1.77250 .nu..sub.16 49.77r.sub.17 154.764 d.sub.17 2.000 N.sub.17 1.00000r.sub.18 .infin. d.sub.18 8.600 N.sub.18 1.51680 .nu..sub.18 64.12r.sub.19 .infin.d.sub.4 = 12.879-6.587-1.000 d.sub.8 = 3.300-9.815-12.801______________________________________ TABLE 9______________________________________Embodiment 9f = 10.2-19.8 F = l.63--1.63Radius of Axial Refractive AbbeCurvature Distance Index (Nd) Number (.nu.d)______________________________________r.sub.1 26.667 d.sub.1 1.300 N.sub.1 1.84666 .nu..sub.1 23.8r.sub.2 18.416 d.sub.2 1.200 N.sub.2 1.00000r.sub.3 21.997 d.sub.3 3.800 N.sub.3 1.71300 .nu..sub.3 53.9r.sub.4 -123.452 d.sub.4 11.434 N.sub.4 1.00000r.sub.5 -56.919 d.sub.5 1.000 N.sub.5 1.71300 .nu..sub.5 53.9r.sub.6 9.489 d.sub.6 1.700 N.sub.6 1.00000r.sub.7 9.877 d.sub.7 2.300 N.sub.7 1.84666 .nu..sub.7 23.8r.sub.8 12.643 d.sub.8 2.900 N.sub.8 1.00000r.sub.9 .infin. d.sub.9 1.700 N.sub.9 1.00000r.sub.10 -44.421 d.sub.10 2.100 N.sub.10 1.77250 .nu..sub.10 49.8r.sub.11 -15.558 d.sub.11 0.100 N.sub.11 1.00000r.sub.12 8.472 d.sub.12 2.700 N.sub.12 1.77250 .nu..sub.12 49.8r.sub.13 -222.090 d.sub.13 0.600 N.sub.13 1.00000r.sub.14 -28.988 d.sub.14 4.007 N.sub.14 1.80518 .nu..sub.14 25.4r.sub.15 7.070 d.sub.15 1.280 N.sub.15 1.00000r.sub.16 17.346 d.sub.16 3.500 N.sub.16 1.78831 .nu..sub.16 47.3r.sub.17 -16.442 d.sub.17 2.000 N.sub.17 1.00000r.sub.18 .infin. d.sub.18 8.600 N.sub.18 1.51680 .nu..sub.18 64.1r.sub.19 .infin.d4 = 11.434-6.261-1.000 d8 = 2.900-9.569-13.063______________________________________ TABLE 10______________________________________Embodiment 10f = 9.2-17.8 F = l.63-1.70Radius of Axial Refractive AbbeCurvature Distance Index (Nd) Number (.nu.d)______________________________________r.sub.1 23.051 d.sub.1 1.200 N.sub.1 1.80518 .nu..sub.1 25.4r.sub.2 15.500 d.sub.2 1.200 N.sub.2 1.00000r.sub.3 19.468 d.sub.3 3.800 N.sub.3 1.69680 .nu..sub.3 56.5r.sub.4 -89.943 d.sub.4 10.456 N.sub.4 1.00000r.sub.5 -56.506 d.sub.5 0.900 N.sub.5 1.69680 .nu..sub.5 56.5r.sub.6 7.875 d.sub.6 1.600 N.sub.6 1.00000r.sub.7 8.642 d.sub.7 2.300 N.sub.7 1.80518 .nu..sub.7 25.4r.sub.8 11.093 d.sub.8 2.600 N.sub.8 1.00000r.sub.9 .infin. d.sub.9 1.600 N.sub.9 1.00000r.sub.10 -45.904 d.sub.10 2.000 N.sub.10 1.77250 .nu..sub.10 49.8r.sub.11 -13.741 d.sub.11 0.100 N.sub.11 1.00000r.sub.12 7.716 d.sub.12 2.700 N.sub.12 1.77250 .nu..sub.12 49.8r.sub.13 -143.394 d.sub.13 0.550 N.sub.13 1.00000r.sub.14 -26.296 d.sub.14 2.849 N.sub.14 1.80518 .nu..sub.14 25.4r.sub.15 6.193 d.sub.15 1.200 N.sub.15 1.00000r.sub.16 15.035 d.sub.16 3.100 N.sub.16 1.78831 .nu..sub.16 47.3r.sub.17 -18.193 d.sub.17 1.500 N.sub.17 1.00000r.sub.18 .infin. d.sub.18 8.500 N.sub.18 1.51680 .nu..sub.18 64.1r.sub.19 .infin.d.sub.4 = 10.456-5.567-1.000 d.sub.8 = 2.600-8.388-11.182______________________________________ TABLE 11______________________________________Embodiment 11f = 9.2-22.2 F = 1.63-1.71Radius of Axial Refractive AbbeCurvature Distance lndex (Nd) Number (.nu.d)______________________________________r.sub.1 25.974 d.sub.1 1.300 N.sub.1 1.84666 .nu..sub.1 23.8r.sub.2 16.978 d.sub.2 1.200 N.sub.2 1.00000r.sub.3 19.394 d.sub.3 4.900 N.sub.3 1.71300 .nu..sub.3 53.9r.sub.4 -119.470 d.sub.4 13.316 N.sub.4 1.00000r.sub.5 -85.161 d.sub.5 0.900 N.sub.5 1.77250 .nu..sub.5 49.8r.sub.6 8.127 d.sub.6 1.500 N.sub.6 1.00000r.sub.7 8.753 d.sub.7 2.400 N.sub.7 1.84666 .nu..sub.7 23.8r.sub.8 11.363 d.sub.8 2.700 N.sub.8 1.00000r.sub.9 .infin. d.sub.9 1.600 N.sub.9.00000r.sub.10 -84.542 d.sub.10 2.300 N.sub.10 1.77250 .nu..sub.10 49.8r.sub.11 -16.024 d.sub.11 0.100 N.sub.11 1.00000r.sub.12 8.265 d.sub.12 2.900 N.sub.12 1.77250 .nu..sub.12 49.8r.sub.13 -273.002 d.sub.13 0.400 N.sub.13 1.00000r.sub.14 -38.094 d.sub.14 3.500 N.sub.14 1.80518 .nu..sub.14 25.4r.sub.15 6.241 d.sub.15 1.000 N.sub.15 1.00000r.sub.16 13.884 d.sub.16 2.900 N.sub.16 1.78831 .nu..sub.16 47.3r.sub.17 -27.012 d.sub.17 1.500 N.sub.17 1.00000r.sub.18 .infin. d.sub.18 8.500 N.sub.18 1.51680 .nu..sub.18 64.1r.sub.19 .infin.d.sub.4 = 13.316-8.211-1.000 d.sub.8 = 2.700-9.666-13.743______________________________________ TABLE 12______________________________________Embodiment 12f = 9.2-17.8 F = 1.52-1.61Radius of Axial Refractive AbbeCurvature Distance lndex (Nd) Number (.nu.d)______________________________________r.sub.1 25.886 d.sub.1 1.200 N.sub.1 1.80518 .nu..sub.1 25.4r.sub.2 16.437 d.sub.2 1.550 N.sub.2 1.00000r.sub.3 19.397 d.sub.3 3.800 N.sub.3 1.69680 .nu..sub.3 56.5r.sub.4 -99.352 d.sub.4 11.688 N.sub.4 1.00000r.sub.5 -43.601 d.sub.5 0.900 N.sub.5 1.69680 .nu..sub.5 56.5r.sub.6 7.705 d.sub.6 1.400 N.sub.6 1.00000r.sub.7 8.550 d.sub.7 2.500 N.sub.7 1.80518 .nu..sub.7 25.4r.sub.8 11.690 d.sub.8 2.600 N.sub.8 1.00000r.sub.9 .infin. d.sub.9 1.600 N.sub.9 1.00000r.sub.10 -39.214 d.sub.10 2.100 N.sub.10 1.77250 .nu..sub.10 49.8r.sub.11 -13.591 d.sub.11 0.100 N.sub.11 1.00000r.sub.12 8.543 d.sub.12 2.800 N.sub.12 1.77250 .nu..sub.12 49.8r.sub.13 -38.610 d.sub.13 0.700 N.sub.13 1.00000r.sub.14 -17.753 d.sub.14 3.400 N.sub.14 1.80518 .nu..sub.14 25.4r.sub.15 7.121 d.sub.15 0.900 N.sub.15 1.00000r.sub.16 17.264 d.sub.16 3.100 N.sub.16 1.78831 .nu..sub.16 47.3r.sub.17 -15.192 d.sub.17 1.500 N.sub.17 1.00000r.sub.18 .infin. d.sub.18 8.500 N.sub.18 1.51680 .nu..sub.18 64.1r.sub.19 .infin.d.sub.4 = 11.688-6.162-1.000 d.sub.8 = 2.600-7.321-9.599______________________________________ TABLE 13______________________________________Embodiment 13f = 9.2-17.8 F = 1.52-1.65Radius of Axial Refractive AbbeCurvature Distance lndex (Nd) Number (.nu.d)______________________________________r.sub.1 25.886 d.sub.1 1.200 N.sub.1 1.80518 .nu..sub.1 25.4r.sub.2 16.437 d.sub.2 1.550 N.sub.2 1.00000r.sub.3 20.247 d.sub.3 3.800 N.sub.3 1.69680 .nu..sub.3 56.5r.sub.4 -81.416 d.sub.4 11.726 N.sub.4 1.00000r.sub.5 -47.194 d.sub.5 0.900 N.sub.5 1.69680 .nu..sub.5 56.5r.sub.6 7.686 d.sub.6 1.400 N.sub.6 1.00000r.sub.7 8.472 d.sub.7 2.500 N.sub.7 1.80518 .nu..sub.7 25.4r.sub.8 11.395 d.sub.8 2.600 N.sub.8 1.00000r.sub.9 .infin. d.sub.9 1.600 N.sub.9 1.00000r.sub.10 -42.162 d.sub.10 2.200 N.sub.10 1.77250 .nu..sub.10 49.8r.sub.11 -13.321 d.sub.11 0.100 N.sub.11 1.00000r.sub.12 8.173 d.sub.12 2.800 N.sub.12 1.77250 .nu..sub.12 49.8r.sub.13 -78.403 d.sub.13 0.600 N.sub.13 1.00000r.sub.14 -23.791 d.sub.14 3.400 N.sub.14 1.80518 .nu..sub.14 25.4r.sub.15 6.337 d.sub.15 2.100 N.sub.15 1.00000r.sub.16 14.630 d.sub.16 3.100 N.sub.16 1.78831 .nu..sub.16 47.3r.sub.17 -15.984 d.sub.17 1.500 N.sub.17 1.00000r.sub.18 .infin. d.sub.18 8.500 N.sub.18 1.51680 .nu..sub.18 64.1r.sub.19 .infin.d.sub.4 = 11.726-6.180-1.000 d.sub.8 = 2.600-7.304-9.574______________________________________ TABLE 14______________________________________Embodiment 14f = 10.2-19.8 F = 1.63-1.65Radius of Axial Refractive AbbeCurvature Distance lndex (Nd) Number (.nu.d)______________________________________r.sub.1 26.316 d.sub.1 1.300 N.sub.1 1.84666 .nu..sub.1 23.8r.sub.2 18.182 d.sub.2 1.200 N.sub.2 1.00000r.sub.3 20.063 d.sub.3 3.900 N.sub.3 1.71300 .nu..sub.3 53.9r.sub.4 -225.240 d.sub.4 10.792 N.sub.4 1.00000r.sub.5 -97.351 d.sub.5 0.900 N.sub.5 1.71300 .nu..sub.5 53.9r.sub.6 8.911 d.sub.6 1.500 N.sub.6 1.00000r.sub.7 9.466 d.sub.7 2.200 N.sub.7 1.84666 .nu..sub.7 23.8r.sub.8 12.066 d.sub.8 2.700 N.sub.8 1.00000r.sub.9 .infin. d.sub.9 2.000 N.sub.9 1.00000r.sub.10 -56.792 d.sub.10 2.200 N.sub.10 1.77250 .nu..sub.10 49.8r.sub.11 -16.301 d.sub.11 0.100 N.sub.11 1.00000r.sub.12 8.548 d.sub.12 2.600 N.sub.12 1.77250 .nu..sub.12 49.8r.sub.13 -2584.881 d.sub.13 0.500 N.sub.13 1.00000r.sub.14 -32.555 d.sub.14 2.600 N.sub.14 1.80518 .nu..sub.14 25.4r.sub.15 7.337 d.sub.15 1.500 N.sub.15 1.00000r.sub.16 20.249 d.sub.16 3.600 N.sub.16 1.78831 .nu..sub.16 47.3r.sub.17 -16.112 d.sub.17 2.000 N.sub.17 1.00000r.sub.18 .infin. d.sub.18 8.600 N.sub.18 1.51680 .nu..sub.18 64.1r.sub.19 .infin.d4 = 10.792-5.937-1.000 d8 = 2.700-10.029-13.867______________________________________ TABLE 15______________________________________Embodiment 15f = 12.3-25.0 F = 1.63--1.63Radius of Axial Refractive AbbeCurvature Distance lndex (Nd) Number (.nu.d)______________________________________r.sub.1 37.410 d.sub.1 1.300 N.sub.1 1.80518 .nu..sub.1 25.4r.sub.2 20.361 d.sub.2 3.800 N.sub.2 1.69100 .nu..sub.2 54.8r.sub.3 -218.664 d.sub.3 15.027 N.sub.3 1.00000r.sub.4 -39.715 d.sub.4 1.000 N.sub.4 1.69750 .nu..sub.4 48.3r.sub.5 8.436 d.sub.5 2.900 N.sub.5 1.8.518 .nu..sub.5 25.4r.sub.6 18.078 d.sub.6 2.900 N.sub.6 1.00000r.sub.7 .infin. d.sub.7 1.500 N.sub.7 1.00000r.sub.8 94.840 d.sub.8 2.100 N.sub.8 1.77250 .nu..sub.8 49.8r.sub.9 -27.124 d.sub.9 0.100 N.sub.9 1.00000r.sub.10 9.372 d.sub.10 2.900 N.sub.10 1.77250 .nu..sub.10 49.8r.sub.11 956.700 d.sub.11 0.500 N.sub.11 1.00000r.sub.12 -42.350 d.sub.12 3.900 N.sub.12 1.80518 .nu..sub.12 25.4r.sub.13 7.258 d.sub.13 1.400 N.sub.13 1.00000r.sub.14 3.904 d.sub.14 3.400 N.sub.14 1.78831 .nu..sub.14 47.3r.sub.15 -14.918 d.sub.15 2.000 N.sub.15 1.00000r.sub.16 .infin. d.sub.16 8.600 N.sub.16 1.51680 .nu..sub.16 64.1r.sub.17 .infin.d.sub.3 = 15.027-8.862-1.500 d.sub.6 = 2.900-12.670-18.410______________________________________ TABLE 16______________________________________Embodiment 16f = 8.2-15.8 F = 1.53-1.63Radius of Axial Refractive AbbeCurvature Distance lndex (Nd) Number (.nu.d)______________________________________r.sub.1 21.053 d.sub.1 1.200 N.sub.1 1.84666 .nu..sub.1 23.8r.sub.2 14.706 d.sub.2 1.200 N.sub.2 1.00000r.sub.3 17.065 d.sub.3 4.400 N.sub.3 1.71300 .nu..sub.3 53.9r.sub.4 -102.184 d.sub.4 8.420 N.sub.4 1.00000r.sub.5 -111.124 d.sub.5 0.900 N.sub.5 1.71300 .nu..sub.5 53.9r.sub.6 6.982 d.sub.6 1.500 N.sub.6 1.00000r.sub.7 6.976 d.sub.7 2.000 N.sub.7 1.84600 .nu..sub.7 23.8r.sub.8 7.805 d.sub.8 2.500 N.sub.8 1.00000r.sub.9 .infin. d.sub.9 1.600 N.sub.9 1.00000r.sub.10 8.831 d.sub.10 3.000 N.sub.10 1.78831 .nu..sub.10 47.3r.sub.11 -27.694 d.sub.11 1.900 N.sub.11 1.00000r.sub.12 -8.498 d.sub.12 2.700 N.sub.12 1.84666 .nu..sub.12 23.8r.sub.13 12.290 d.sub.13 0.700 N.sub.13 1.00000r.sub.14 -1269.454 d.sub.14 3.000 N.sub.14 1.78831 .nu..sub.14 47.3r.sub.15 -9.120 d.sub.15 0.100 N.sub.15 1.00000r.sub.16 10.662 d.sub.16 3.100 N.sub.16 1.78831 .nu..sub.16 47.3r.sub.17 86.436 d.sub.17 2.000 N.sub.17 1.00000r.sub.18 .infin. d.sub.18 8.600 N.sub.18 1.51680 .nu..sub.18 64.1r.sub.19 .infin.d.sub.4 = 8.420-4.386-1.000 d.sub.8 = 2.500-6.534-9.919d.sub.9 = 1.600-1.417-1.602 d.sub.17 = 2.000-2.183-1.998______________________________________ TABLE 17______________________________________Embodiment 17f = 8.2-15.8 F = 1.44-1.52Radius of Axial Refractive AbbeCurvature Distance lndex (Nd) Number (.nu.d)______________________________________r.sub.1 21.865 d.sub.1 1.200 N.sub.1 1.84666 .nu..sub.1 23.8r.sub.2 15.309 d.sub.2 1.200 N.sub.2 1.00000r.sub.3 18.469 d.sub.3 4.600 N.sub.3 1.71300 .nu..sub.3 53.9r.sub.4 -87.899 d.sub.4 8.663 N.sub.4 1.00000r.sub.5 -96.202 d.sub.5 0.900 N.sub.5 1.71300 .nu..sub.5 53.9r.sub.6 7.610 d.sub.6 1.800 N.sub.6 1.00000r.sub.7 7.573 d.sub.7 2.300 N.sub.7 1.84666 .nu..sub.7 23.8r.sub.8 8.174 d.sub.8 2.600 N.sub.8 1.00000r.sub.9 .infin. d.sub.9 1.600 N.sub.9 1.00000r.sub.10 9.203 d.sub.10 3.200 N.sub.10 1.77250 .nu..sub.10 49.8r.sub.11 -30.213 d.sub.11 2.000 N.sub.11 1.00000r.sub.12 -9.498 d.sub.12 2.900 N.sub.12 1.84666 .nu..sub.12 23.8r.sub.13 11.899 d.sub.13 0.900 N.sub.13 1.00000r.sub.14 155.257 d.sub.14 3.400 N.sub.14 1.77250 .nu..sub.14 49.8r.sub.15 -10.430 d.sub.15 0.100 N.sub.15 1.00000r.sub.16 11.492 d.sub.16 4.200 N.sub.16 1.77250 .nu..sub.16 49.8r.sub.17 -188.336 d.sub.17 2.000 N.sub.17 1.00000r.sub.18 .infin. d.sub.18 8.600 N.sub.18 1.51680 .nu..sub.18 64.1r.sub.19 .infin.d.sub.4 = 8.663-4.533-1.000 d.sub.8 = 2.600-6.730-10.263d.sub.9 = 1.600-1.498-1.718 d.sub.17 = 2.000-2.102-1.882______________________________________ TABLE 18______________________________________Embodiment 18f = 9.2-17.8 F = 1.54-1.69Radius of Axial Refractive AbbeCurvature Distance lndex (Nd) Number (.nu.d)______________________________________r.sub.1 22.523 d.sub.1 1.300 N.sub.1 1.84666 .nu..sub.1 23.8r.sub.2 16.313 d.sub.2 1.400 N.sub.2 1.00000r.sub.3 22.834 d.sub.3 4.000 N.sub.3 1.71300 .nu..sub.3 53.9r.sub.4 -73.034 d.sub.4 9.639 N.sub.4 1.00000r.sub.5 -74.054 d.sub.5 1.000 N.sub.5 1.71300 .nu..sub.5 53.9r.sub.6 8.398 d.sub.6 1.900 N.sub.6 1.00000r.sub.7 8.527 d.sub.7 2.200 N.sub.7 1.84666 .nu..sub.7 23.8r.sub.8 9.738 d.sub.8 2.700 N.sub.8 1.00000r.sub.9 .infin. d.sub.9 1.500 N.sub.9 1.00000r.sub.10 10.039 d.sub.10 3.800 N.sub.10 1.78831 .nu..sub.10 47.3r.sub.11 -27.952 d.sub.11 1.700 N.sub.11 1.00000r.sub.12 -11.342 r.sub.12 3.100 N.sub.12 1.84666 .nu..sub.12 23.8r.sub.13 11.656 d.sub.13 0.900 N.sub.13 1.00000r.sub.14 103.090 d.sub.14 2.800 N.sub.14 1.78831 .nu..sub.14 47.3r.sub.15 -13.056 d.sub.15 0.100 N.sub.15 1.00000r.sub.16 12.383 d.sub.16 3.700 N.sub.16 1.77250 .nu..sub.16 49.8r.sub.17 -1026.032 d.sub.17 2.000 N.sub.17 1.00000r.sub.18 .infin. d.sub.18 8.600 N.sub.18 1.51680 .nu..sub.18 64.1r.sub.19 .infin.d.sub.4 = 8.639-4.560-1.000 d.sub.8 = 2.700-7.779-11.339d.sub.9 = 1.500-1.581-1.905 d.sub.17 = 2.000-1.919-1.595______________________________________ TABLE 19______________________________________Embodiment 19f = 9.2-17.8 F = 1.61-1.74Radius of Axial Refractive AbbeCurvature Distance lndex (Nd) Number (.nu.d)______________________________________r.sub.1 23.810 d.sub.1 12.00 N.sub.1 1.80518 .nu..sub.1 25.4r.sub.2 16.129 d.sub.2 1.300 N.sub.2 1.00000r.sub.3 22.297 d.sub.3 3.800 N.sub.3 1.71300 .nu..sub.3 53.9r.sub.4 -65.151 d.sub.4 9.466 N.sub.4 1.00000r.sub.5 -57.191 d.sub.5 1.000 N.sub.5 1.71300 .nu..sub.5 53.9r.sub.6 8.421 d.sub.6 1.800 N.sub.6 1.00000r.sub.7 8.465 d.sub.7 2.200 N.sub.7 1.84666 .nu..sub.7 23.8r.sub.8 9.830 d.sub.8 2.600 N.sub.8 1.00000r.sub.9 .infin. d.sub.9 1.500 N.sub.9 1.00000r.sub.10 9.231 d.sub.10 3.600 N.sub.10 1.77250 .nu..sub.10 49.8r.sub.11 -26.549 d.sub.11 1.900 N.sub.11 1.00000r.sub.12 -9.520 d.sub.12 2.800 N.sub.12 1.80518 .nu..sub.12 25.4r.sub.13 11.086 d.sub.13 0.900 N.sub.13 1.00000r.sub.14 158.556 d.sub.14 2.700 N.sub.14 1.77250 .nu..sub.14 49.8r.sub.15 -12.130 d.sub.15 0.100 N.sub.15 1.00000r.sub.16 12.569 d.sub.16 3.400 N.sub.16 1.77250 .nu..sub.16 49.8r.sub.17 -567.082 d.sub.17 2.000 N.sub.17 1.00000r.sub.18 .infin. d.sub.18 8.600 N.sub.18 1.51680 .nu..sub.18 64.1r.sub.19 .infin.d.sub.4 = 9.466-4.498-1.000 d.sub.8 = 2.600-7.569-11.067d.sub.9 = 1.500-1.721-2.110 d.sub.17 = 2.000-1.779-1.390______________________________________ TABLE 20______________________________________Embodiment 20f = 9.2-20.3 F = 1.61-1.75Radius of Axial Refractive AbbeCurvature Distance lndex (Nd) Number (.nu.d)______________________________________r.sub.1 25.598 d.sub.1 1.200 N.sub.1 1.80518 .nu..sub.1 25.4r.sub.2 16.831 d.sub.2 1.100 N.sub.2 1.00000r.sub.3 21.347 d.sub.3 4.200 N.sub.3 1.71300 .nu..sub.3 53.9r.sub.4 -73.662 d.sub.4 11.334 N.sub.4 1.00000r.sub.5 -60.811 d.sub.5 1.000 N.sub.5 1.71300 .nu..sub.5 53.9r.sub.6 8.651 d.sub.6 1.900 N.sub.6 1.00000r.sub.7 8.457 d.sub.7 2.200 N.sub.7 1.84666 .nu..sub.7 23.8r.sub.8 9.546 d.sub.8 2.600 N.sub.8 1.00000r.sub.9 .infin. d.sub.9 1.500 N.sub.9 1.00000r.sub.10 9.944 d.sub.10 3.900 N.sub.10 1.78831 .nu..sub.10 47.3r.sub.11 -23.192 d.sub.11 1.600 N.sub.11 1.00000r.sub.12 -10.234 d.sub.12 4.000 N.sub.12 1.80518 .nu..sub.12 25.4r.sub.13 11.457 d.sub.13 0.900 N.sub.13 1.00000r.sub.14 70.576 d.sub.14 2.700 N.sub.14 1.77250 .nu..sub.14 49.8r.sub.15 -13.770 d.sub.15 0.100 N.sub.15 1.00000r.sub.16 12.779 d.sub.16 3.300 N.sub.16 1.77250 .nu..sub.16 49.8r.sub.17 231.473 d.sub.17 2.000 N.sub.17 1.00000r.sub.18 .infin. d.sub.18 8.600 N.sub.18 1.51680 .nu..sub.18 64.1r.sub.19 .infin.d.sub.4 = 11.334-5.601-1.000 d.sub.8 = 2.600-8.333-12.934d.sub.9 = 1.500-1.415-1.866 d.sub.17 = 2.000-2.085-1.634______________________________________ TABLE 21______________________________________Embodiment 21f = 8.2-15.8 F = 1.53-1.63Radius of Axial Refractive AbbeCurvature Distance lndex (Nd) Number (.nu.d)______________________________________r.sub.1 21.317 d.sub.1 1.200 N.sub.1 1.84666 .nu..sub.1 23.8r.sub.2 14.351 d.sub.2 1.200 N.sub.2 1.00000r.sub.3 16.766 d.sub.3 4.500 N.sub.3 1.71300 .nu..sub.3 53.9r.sub.4 -90.680 d.sub.4 8.398 N.sub.4 1.00000r.sub.5 -80.837 d.sub.5 0.900 N.sub.5 1.71300 .nu..sub.5 53.9r.sub.6 6.961 d.sub.6 1.500 N.sub.6 1.00000r.sub.7 7.082 d.sub.7 2.000 N.sub.7 1.84666 .nu.7 23.8r.sub.8 8.120 d.sub.8 2.500 N.sub.8 1.00000r.sub.9 .infin. d.sub.9 1.600 N.sub.9 1.00000r.sub.10 8.607 d.sub.10 3.000 N.sub.10 1.78831 .nu..sub.10 47.3r.sub.11 -19.673 d.sub.11 1.900 N.sub.11 1.00000r.sub.12 -7.328 d.sub.12 2.700 N.sub.12 1.84666 .nu..sub.12 23.8r.sub.13 12.548 d.sub.13 0.700 N.sub.13 1.00000r.sub.14 -159.427 d.sub.14 3.100 N.sub.14 1.78831 .nu..sub.14 47.3r.sub.15 -9.046 d.sub.15 0.100 N.sub.15 1.00000r.sub.16 11.398 d.sub.16 3.000 N.sub.16 1.78831 .nu..sub.16 47.3r.sub.17 240.408 d.sub.17 2.000 N.sub.17 1.00000r.sub.18 .infin. d.sub.18 8.600 N.sub.18 1.51680 .nu..sub.18 64.1r.sub.19 .infin.d.sub.4 = 8.398-4.383-1.000 d.sub.8 = 2.500-6.515-9.898d.sub.9 = 1.600-1.495-1.727 d.sub.17 = 2.000-2.105-1.873______________________________________ TABLE 22______________________________________Embodiment 22f = 10.2-19.8 F = 1.63-1.75Radius of Axial Refractive AbbeCurvature Distance lndex (Nd) Number (.nu.d)______________________________________r.sub.1 26.786 d.sub.1 1.300 N.sub.1 1.84666 .nu..sub.1 23.8r.sub.2 17.279 d.sub.2 1.200 N.sub.2 1.00000r.sub.3 20.612 d.sub.3 3.900 N.sub.3 1.71300 .nu..sub.3 53.9r.sub.4 -108.133 d.sub.4 11.089 N.sub.4 1.00000r.sub.5 -49.914 d.sub.5 1.000 N.sub.5 1.71300 .nu..sub.5 53.9r.sub.6 9.569 d.sub.6 1.700 N.sub.6 1.00000r.sub.7 9.914 d.sub.7 2.300 N.sub.7 1.84666 .nu..sub.7 23.8r.sub.8 12.779 d.sub.8 2.900 N.sub.8 1.00000r.sub.9 .infin. d.sub.9 1.600 N.sub.9 1.00000r.sub.10 -62.323 d.sub.10 1.900 N.sub.10 1.77250 .nu..sub.10 49.8r.sub.11 -15.759 d.sub.11 0.100 N.sub.11 1.00000r.sub.12 8.558 d.sub.12 2.700 N.sub.12 1.77250 .nu..sub.12 49.8r.sub.13 -242.796 d.sub.13 0.600 N.sub.13 1.00000r.sub.14 -31.879 d.sub.14 4.000 N.sub.14 1.80518 .nu..sub.14 25.4r.sub.15 6.669 d.sub.15 1.200 N.sub.15 1.00000r.sub.16 16.482 d.sub.16 2.894 N.sub.16 1.78831 .nu..sub.16 47.3r.sub.17 -21.289 d.sub.17 2.000 N.sub.17 1.00000r.sub.18 .infin. d.sub.18 8.600 N.sub.18 1.51680 .nu..sub.18 64.1r.sub.19 .infin.d.sub.4 = 11.089-5.237-1.000 d.sub.8 = 2.900-8.751-12.989d.sub.9 = 1.600-1.516-1.807 d.sub.17 = 2.000-2.084-1.793______________________________________ TABLE 23______________________________________Embodiment 23f = 10.2-19.8 F = 1.53--1.53Radius of Axial Refractive AbbeCurvature Distance Index (Nd) Number ( .nu.d)______________________________________r.sub.1 26.737 d.sub.1 1.300 N.sub.1 1.84666 .nu..sub.1 23.8r.sub.2 17.165 d.sub.2 1.300 N.sub.2 1.00000r.sub.3 19.729 d.sub.3 3.950 N.sub.3 1.71300 .nu..sub.3 53.9r.sub.4 -129.683 d.sub.4 11.007 N.sub.4 1.00000r.sub.5 -57.733 d.sub.5 1.000 N.sub.5 1.71300 .nu..sub.5 53.9r.sub.6 9.296 d.sub.6 1.700 N.sub.6 1.00000r.sub.7 9.837 d.sub.7 2.400 N.sub.7 1.84666 .nu..sub.7 23.8r.sub.8 12.555 d.sub.8 2.800 N.sub.8 1.00000r.sub.9 .infin. d.sub.9 1.600 N.sub.9 1.00000r.sub.10 -75.036 d.sub.10 2.100 N.sub.10 1.77250 .nu..sub.10 49.8r.sub.11 -16.680 d.sub.11 0.100 N.sub.11 1.00000r.sub.12 8.824 d.sub.12 2.900 N.sub.12 1.77250 .nu..sub.12 49.8r.sub.13 -142.727 d.sub.13 0.500 N.sub.13 1.00000r.sub.14 -31.305 d.sub.14 3.900 N.sub.14 1.80518 .nu..sub.14 25.4r.sub.15 6.935 d.sub.15 1.100 N.sub.15 1.00000r.sub.16 17.800 d.sub.16 2.800 N.sub.16 1.78831 .nu..sub.16 47.3r.sub.17 -19.209 d.sub.17 2.000 N.sub.17 1.00000r.sub.18 .infin. d.sub.18 8.600 N.sub.18 1.51680 .nu..sub.18 64.1r.sub.19 .infin.d.sub.4 = 11.007-5.196-1.000 d.sub.8 = 2.800-8.611-12.807d.sub.9 = 1.600-1.477-1.753 d.sub.17 = 2.000-2.123-1.847______________________________________ TABLE 24______________________________________Embodiment 24f = 9.2-17.8 F = 1.53--1.53Radius of Axial Refractive AbbeCurvature Distance Index (Nd) Number (.nu.d)______________________________________r.sub.1 25.189 d.sub.1 1.200 N.sub.1 1.80518 .nu..sub.1 25.4r.sub.2 15.504 d.sub.2 1.200 N.sub.2 1.00000r.sub.3 18.067 d.sub.3 3.900 N.sub.3 1.71300 .nu..sub.3 53.9r.sub.4 -91.379 d.sub.4 10.000 N.sub.4 1.00000r.sub.5 -51.627 d.sub.5 0.900 N.sub.5 1.71300 .nu..sub.5 53.9r.sub.6 8.454 d.sub.6 1.600 N.sub.6 1.00000r.sub.7 8.991 d.sub.7 2.200 N.sub.7 1.84666 .nu..sub.7 25.4r.sub.8 11.387 d.sub.8 2.700 N.sub.8 1.00000r.sub.9 .infin. d.sub.9 1.500 N.sub.9 1.00000r.sub.10 -77.501 d.sub.10 2.000 N.sub.10 1.77250 .nu..sub.10 49.8r.sub.11 -15.466 d.sub.11 0.100 N.sub.11 1.00000r.sub.12 8.071 d.sub.12 2.700 N.sub.12 1.77250 .nu..sub.12 49.8r.sub.13 -100.462 d.sub.13 0.400 N.sub.13 1.00000r.sub.14 -28.780 d.sub.14 3.200 N.sub.14 1.80518 .nu..sub.14 25.4r.sub.15 6.382 d.sub.15 1.050 N.sub.15 1.00000r.sub.16 16.154 d.sub.16 2.700 N.sub.16 1.78831 .nu..sub.16 47.3r.sub.17 -17.880 d.sub.17 1.500 N.sub.17 1.00000r.sub.18 .infin. d.sub.18 8.500 N.sub.18 1.51680 .nu..sub.18 64.1r.sub.19 .infin.d.sub.4 = 10.007-5.129-1.000 d.sub.8 = 2.700-7.570-11.700d.sub.9 = 1.500-1.274-1.489 d.sub.17 = 1.500-1.726-1.511______________________________________ TABLE 25______________________________________Embodiment 25f = 10.2-24.7 F = 1.61--1.61Radius of Axial Refractive AbbeCurvature Distance Index (Nd) Number (.nu.d)______________________________________r.sub.1 26.712 d.sub.1 1.300 N.sub.1 1.84666 .nu..sub.1 23.8r.sub.2 17.301 d.sub.2 1.300 N.sub.2 1.00000r.sub.3 18.791 d.sub.3 3.950 N.sub.3 1.71300 .nu..sub.3 53.9r.sub.4 -236.859 d.sub.4 14.241 N.sub.4 1.00000r.sub.5 -59.993 d.sub.5 1.000 N.sub.5 1.71300 .nu..sub.5 53.9r.sub.6 9.509 d.sub.6 1.700 N.sub.6 1.00000r.sub.7 9.730 d.sub.7 2.400 N.sub.7 1.84666 .nu..sub.7 23.8r.sub.8 11.661 d.sub.8 2.800 N.sub.8 1.00000r.sub.9 .infin. d.sub.9 1.800 N.sub.9 1.00000r.sub.10 -383.646 d.sub.10 2.200 N.sub.10 1.77250 .nu..sub.10 49.8r.sub.11 -18.476 d.sub.11 0.100 N.sub.11 1.00000r.sub.12 8.892 d.sub.12 3.000 N.sub.12 1.77250 .nu..sub.12 49.8r.sub.13 -188.536 d.sub.13 0.500 N.sub.13 1.00000r.sub.14 -37.863 d.sub.14 4.100 N.sub.14 1.80518 .nu..sub.14 25.4r.sub.15 6.559 d.sub.15 1.200 N.sub.15 1.00000r.sub.16 20.685 d.sub.16 2.800 N.sub.16 1.78831 .nu..sub.16 47.3r.sub.17 -23.562 d.sub.17 2.000 N.sub.17 1.00000r.sub.18 .infin. d.sub.18 8.600 N.sub.18 1.51680 .nu..sub.18 64.1r.sub.19 .infin.d.sub.4 = 14.241-6.096-1.000 d.sub.8 = 2.800-10.945-16.041d.sub.9 = 1.800-1.179-1.600 d.sub.17 = 2.000-2.621-2.200______________________________________ TABLE 26______________________________________Embodiment 26f = 9.2-26.3 F = 1.63--1.63Radius of Axial Refractive AbbeCurvature Distance lndex (Nd) Number (.nu.d)______________________________________r.sub.1 27.495 d.sub.1 1.300 N.sub.1 1.80518 .nu..sub.1 25.4r.sub.2 17.599 d.sub.2 1.300 N.sub.2 1.00000r.sub.3 19.300 d.sub.3 5.600 N.sub.3 1.69100 .nu..sub.3 54.8r.sub.4 -139.004 d.sub.4 14.736 N.sub.4 1.00000r.sub.5 18.486 d.sub.5 0.900 N.sub.5 1.77250 .nu..sub.5 49.8r.sub.6 10.170 d.sub.6 3.000 N.sub.6 1.00000r.sub.7 -17.232 d.sub.7 0.900 N.sub.7 1.69350 .nu..sub.7 50.3r.sub.8 11.259 d.sub.8 2.600 N.sub.8 180518 .nu..sub.8 25.4r.sub.9 69.596 d.sub.9 1.900 N.sub.9 1.00000r.sub.10 .infin. d.sub.10 1.800 N.sub.10 1.00000r.sub.11 10.858 d.sub.11 3.100 N.sub.11 1.77250 .nu..sub.11 49.8r.sub.12 -117.810 d.sub.12 3.000 N.sub.12 1.00000r.sub.13 -12.400 d.sub.13 3.500 N.sub.13 1.80518 .nu..sub.13 25.4r.sub.14 13.840 d.sub.14 0.900 N.sub.14 1.00000r.sub.15 76.945 d.sub.15 2.900 N.sub.15 1.77250 .nu..sub.15 49.8r.sub.16 -13.904 d.sub.16 0.100 N.sub.16 1.00000r.sub.17 13.793 d.sub.17 3.300 N.sub.17 1.77250 .nu..sub.17 49.8r.sub.18 -190.016 d.sub.18 3.000 N.sub.18 1.00000r.sub.19 .infin. d.sub.19 8.600 N.sub.19 1.51680 .nu..sub.19 64.1r.sub.20 .infin.d.sub.4 = 14.736-5.614-0.800 d.sub.8 = 2.600-11.021-15.836d.sub.9 = 1.900-1.223-1.722 d.sub.18 = 3.000-3.577-3.078______________________________________ TABLE 27______________________________________Embodiment 27f = 7.65-14.8 F = 1.63--1.63Radius of Axial Refractive AbbeCurvature Distance lndex (Nd) Number (.nu.d)______________________________________r.sub.1 25.107 d.sub.1 1.200 N.sub.1 1.84666 .nu..sub.1 23.8r.sub.2 15.861 d.sub.2 1.100 N.sub.2 1.00000r.sub.3 18.975 d.sub.3 4.800 N.sub.3 1.77250 .nu..sub.3 49.8r.sub.4 -101.514 d.sub.4 8.218 N.sub.4 1.00000r.sub.5 21.211 d.sub.5 0.900 N.sub.5 1.78100 .nu..sub.5 44.6r.sub.6 8.919 d.sub.6 2.400 N.sub.6 1.00000r.sub.7 -13.384 d.sub.7 0.900 N.sub.7 1.72000 .nu..sub.7 50.3r.sub.8 15.208 d.sub.8 2.000 N.sub.8 1.84666 .nu..sub.8 23.8r.sub.9 -190.190 d.sub.9 1.500 N.sub.9 1.00000r.sub.10 .infin. d.sub.10 1.500 N.sub.10 1.00000r.sub.11 8.334 d.sub.11 2.900 N.sub.11 1.77250 .nu..sub.11 49.8r.sub.12 -33.264 d.sub.12 1.900 N.sub.12 1.00000r.sub.13 -8.910 d.sub.13 1.900 N.sub.13 1.84666 .nu..sub.13 23.8r.sub.14 10.559 d.sub.14 1.000 N.sub.14 1.00000r.sub.15 70.057 d.sub.15 3.300 N.sub.15 1.74250 .nu..sub.15 52.5r.sub.16 -9.925 d.sub.16 0.100 N.sub.16 1.00000r.sub.17 12.062 d.sub.17 3.800 N.sub.17 1.74250 .nu..sub.17 52.5r.sub.18 -91.780 d.sub.18 2.000 N.sub.18 1.00000r.sub.19 .infin. d.sub.19 8.000 N.sub.19 1.51680 .nu..sub.19 64.1r.sub.20 .infin.d.sub.4 = 8.218-4.501-0.800 d.sub.8 = 1.500-5.217-8.918d.sub.9 = 1.500-1.804-2.253 d.sub.18 = 2.000-1.696-1.247______________________________________ TABLE 28______________________________________Embodiment 28f = 9.2-22.2 F = 1.63-1.90Radius of Axial Refractive AbbeCurvature Distance lndex (Nd) Number (.nu.d)______________________________________r.sub.1 27.821 d.sub.1 1.300 N.sub.1 1.84666 .nu..sub.1 23.8r.sub.2 17.042 d.sub.2 1.200 N.sub.2 1.00000r.sub.3 19.503 d.sub.3 4.800 N.sub.3 1.71300 .nu..sub.3 53.9r.sub.4 -90.072 d.sub.4 12.094 N.sub.4 1.00000r.sub.5 41.743 d.sub.5 0.900 N.sub.5 1.78831 .nu..sub.5 47.3r.sub.6 12.210 d.sub.6 2.100 N.sub.6 1.00000r.sub.7 -12.390 d.sub.7 0.900 N.sub.7 1.71700 .nu..sub.7 47.9r.sub.8 15.049 d.sub.8 2.300 N.sub.8 1.80518 .nu..sub.8 25.4r.sub.9 -43.586 d.sub.9 1.500 N.sub.9 1.00000r.sub.10 .infin. d.sub.10 1.500 N.sub.10 1.00000r.sub.11 161.125 d.sub.11 2.100 N.sub.11 1.77250 .nu..sub.11 49.8r.sub.12 -19.907 d.sub.12 0.100 N.sub.12 1.00000r.sub.13 8.020 d.sub.13 2.900 N.sub.13 1.77250 .nu..sub.13 49.8r.sub.14 -6231.694 d.sub.14 0.500 N.sub.14 1.00000r.sub.15 -42.416 d.sub.15 3.500 N.sub.15 1.80518 .nu..sub.15 25.4r.sub.16 5.752 d.sub.16 1.200 N.sub.16 1.00000r.sub.17 16.835 d.sub.17 2.700 N.sub.17 1.78831 .nu..sub.17 47.3r.sub.18 -25.029 d.sub.18 2.000 N.sub.18 1.00000r.sub.19 .infin. d.sub.19 8.500 N.sub.19 1.51680 .nu..sub.19 64.1r.sub.20 .infin.d.sub.4 = 12.094-6.179-0.800 d.sub.8 = 1.500-7.415 -12.794d.sub.9 =1.500-1.603-2.288 d.sub.18 = 2.000-1.897-1.212______________________________________ TABLE 29______________________________________Embodiment 29f = 9.2-26.3 F = 1.63--1.63Radius of Axial Refractive AbbeCurvature Distance Index (Nd) Number (.nu.d)______________________________________r.sub.1 27.544 d.sub.1 1.300 N.sub.1 1.80518 .nu..sub.1 25.4r.sub.2 17.067 d.sub.2 1.300 N.sub.2 1.00000r.sub.3 18.586 d.sub.3 5.700 N.sub.3 1.69100 .nu..sub.3 54.8r.sub.4 -133.219 d.sub.4 14.670 N.sub.4 1.00000r.sub.5 17.832 d.sub.5 0.900 N.sub.5 1.77250 .nu..sub.5 49.8r.sub.6 9.572 d.sub.6 2.900 N.sub.6 1.00000r.sub.7 -16.184 d.sub.7 0.900 N.sub.7 1.69350 .nu..sub.7 50.3r.sub.8 10.878 d.sub.8 2.600 N.sub.8 1.80518 .nu..sub.8 25.4r.sub.9 110.835 d.sub.9 2.000 N.sub.9 1.00000r.sub.10 .infin. d.sub.10 1.500 N.sub.10 1.00000r.sub.11 10.928 d.sub.11 3.100 N.sub.11 1.77250 .nu..sub.11 49.8r.sub. 12 -138.397 d.sub.12 3.250 N.sub.12 1.00000r.sub.13 -12.325 d.sub.13 3.900 N.sub.13 1.84666 .nu..sub.13 23.8r.sub.14 14.638 d.sub.14 0.800 N.sub.14 1.00000r.sub.15 75.983 d.sub.15 3.000 N.sub.15 1.77250 .nu..sub.15 49.8r.sub.16 -13.420 d.sub.16 0.100 N.sub.16 1.00000r.sub.17 13.240 d.sub.17 3.400 N.sub.17 1.77250 .nu..sub.17 49.8r.sub.18 -460.552 d.sub.18 3.000 N.sub.18 1.00000r.sub.19 .infin. d.sub.19 8.600 N.sub.19 1.51680 .nu..sub.19 64.1r.sub.20 .infin.d.sub.4 = 14.670-2.507-0.800 d.sub.9 = 2.000 -15.208 -15.856______________________________________ TABLE 30______________________________________Embodiment 30f = 9.2-22.0 F = 1.63--1.63Radius of Axial Refractive AbbeCurvature Distance Index (Nd) Number (.nu.d)______________________________________r.sub.1 31.580 d.sub.1 1.400 N.sub.1 1.84666 .nu..sub.1 23.8r.sub.2 17.516 d.sub.2 1.350 N.sub.2 1.00000r.sub.3 19.812 d.sub.3 6.000 N.sub.3 1.77250 .nu..sub.3 49.8r.sub.4 -95.136 d.sub.4 12.873 N.sub.4 1.00000r.sub.5 30.621 d.sub.5 1.000 N.sub.5 1.77250 .nu..sub.5 49.8r.sub.6 11.301 d.sub.6 2.300 N.sub.6 1.00000r.sub.7 -15.719 d.sub.7 1.000 N.sub.7 1.71300 .nu..sub.7 53.9r.sub.8 13.920 d.sub.8 2.500 N.sub.8 1.80518 .nu..sub.8 25.4r.sub.9 -192.320 d.sub.9 1.800 N.sub.9 1.00000r.sub.10 .infin. d.sub.10 1.500 N.sub.10 1.00000r.sub.11 9.797 d.sub.11 3.200 N.sub.11 1.77250 .nu..sub.11 49.8r.sub. 12 55.688 d.sub.12 2.200 N.sub.12 1.00000r.sub.13 -12.390 d.sub.13 2.200 N.sub.13 1.84666 .nu..sub.13 23.8r.sub.14 11.506 d.sub.14 1.100 N.sub.14 1.00000r.sub.15 67.549 d.sub.15 3.100 N.sub.15 1.74250 .nu..sub.15 52.5r.sub.16 -12.763 d.sub.16 0.100 N.sub.16 1.00000r.sub.17 13.089 d.sub.17 3.500 N.sub.17 1.74250 .nu..sub.17 52.5r.sub.18 -210.947 d.sub.18 3.000 N.sub.18 1.00000r.sub.19 .infin. d.sub.19 8.500 N.sub.19 1.51680 .nu..sub.19 64.1r.sub.20 .infin.d4 = 12.873-6.965-1.000 d9 = 1.800-9.579- 12.864______________________________________ TABLE 31______________________________________Embodiment 31f = 8.2-15.8 F = 1.63-1.63Radius of Axial Refractive AbbeCurvature Distance Index (Nd) Number (.nu.d)______________________________________r.sub.1 25.123 d.sub.1 1.300 N.sub.1 1.84666 .nu..sub.1 23.8r.sub.2 15.737 d.sub.2 1.200 N.sub.2 1.00000r.sub.3 17.785 d.sub.3 5.200 N.sub.3 1.77250 .nu..sub.3 49.8r.sub.4 -157.789 d.sub.4 10.068 N.sub.4 1.00000r.sub.5 24.698 d.sub.5 0.900 N.sub.5 1.78100 .nu..sub.5 44.6r.sub.6 8.012 d.sub.6 2.500 N.sub.6 1.00000r.sub.7 -11.344 d.sub.7 0.900 N.sub.7 1.71700 .nu..sub.7 47.9r.sub.8 21.312 d.sub.8 2.400 N.sub.8 1.84666 .nu..sub.8 23.8r.sub.9 -29.117 d.sub.9 2.000 N.sub.9 1.00000r.sub.10 .infin. d.sub.10 1.500 N.sub.10 1.00000r.sub.11 .infin. d.sub.11 3.000 N.sub.11 1.77250 .nu..sub.11 49.8r.sub.12 -34.738 d.sub.12 2.100 N.sub.12 1.00000r.sub.13 -10.152 d.sub.13 2.000 N.sub.13 1.84666 .nu..sub.13 23.8r.sub.14 11.027 d.sub.14 1.000 N.sub.14 1.00000r.sub.15 152.547 d.sub.15 3.500 N.sub.15 1.74250 .nu..sub.15 52.5r.sub.16 -10.412 d.sub.16 0.100 N.sub.16 1.00000r.sub.17 11.379 d.sub.17 4.300 N.sub.17 1.74250 .nu..sub.17 52.5r.sub.18 -375.049 d.sub.18 2.000 N.sub.18 1.00000r.sub.19 .infin. d.sub.19 8.600 N.sub.19 1.51680 .nu..sub.19 64.1r.sub.20 .infin.d4 = 12.873-6.965-1.000 d9 = 1.800-9.579 -12.864______________________________________ TABLE 32______________________________________Embodiment 32f = 7.65-14.8 F = 1.63--1.63Radius of Axial Refractive AbbeCurvature Distance Index (Nd) Number (.nu.d)______________________________________r.sub.1 24.331 d.sub.1 1.200 N.sub.1 1.84666 .nu..sub.1 23.8r.sub.2 16.131 d.sub.2 1.100 N.sub.2 1.00000r.sub.3 19.104 d.sub.3 5.700 N.sub.3 1.77250 .nu..sub.3 49.8r.sub.4 -119.429 d.sub.4 9.818 N.sub.4 1.00000r.sub.5 24.423 d.sub.5 0.900 N.sub.5 1.78100 .nu..sub.5 44.6r.sub.6 8.241 d.sub.6 2.400 N.sub.6 1.00000r.sub.7 -11.348 d.sub.7 0.900 N.sub.7 1.71700 .nu..sub.7 47.9r.sub.8 16.762 d.sub.8 2.300 N.sub.8 1.84666 .nu..sub.8 23.8r.sub.9 -38.695 d.sub.9 1.500 N.sub.9 1.00000r.sub.10 .infin. d.sub.10 1.500 N.sub.10 1.00000r.sub.11 9.009 d.sub.11 2.800 N.sub.11 1.77250 .nu..sub.11 49.8r.sub.12 -22.169 d.sub.12 1.900 N.sub.12 1.00000r.sub.13 -8.124 d.sub.13 1.900 N.sub.13 1.84666 .nu..sub.13 23.8r.sub.14 12.121 d.sub.14 1.000 N.sub.14 1.00000r.sub.15 -797.728 d.sub.15 3.300 N.sub.15 1.74250 .nu..sub.15 52.5r.sub.16 -9.076 d.sub.16 0.100 N.sub.16 1.00000r.sub.17 12.014 d.sub.17 4.400 N.sub.17 1.74250 .nu..sub.17 52.5r.sub.18 -67.356 d.sub.18 2.000 N.sub.18 1.00000r.sub.19 .infin. d.sub.19 8.000 N.sub.19 1.51680 .nu..sub.19 64.1r.sub.20 .infin.d4 = 9.818-5.954-1.000 d9 1.500-5.000-7.320______________________________________ TABLE 33______________________________________Embodiment 33f = 9.2-22.2 F = 1.63-1.68Radius of Axial Refractive AbbeCurvature Distance Index (Nd) Number (.nu.d)______________________________________r.sub.1 26.631 d.sub.1 1.300 N.sub.1 1.84666 .nu..sub.1 23.8r.sub.2 17.079 d.sub.2 1.200 N.sub.2 1.00000r.sub.3 18.863 d.sub.3 5.500 N.sub.3 1.71300 .nu..sub.3 53.9r.sub.4 -142.200 d.sub.4 13.359 N.sub.4 1.00000r.sub.5 30.043 d.sub.5 0.900 N.sub.5 1.78831 .nu..sub.5 47.3r.sub.6 11.402 d.sub.6 2.200 N.sub.6 1.00000r.sub.7 -13.585 d.sub.7 0.900 N.sub.7 1.71700 .nu..sub.7 47.9r.sub.8 16.162 d.sub.8 2.200 N.sub.8 1.80518 .nu..sub.8 25.4r.sub.9 -71.183 d.sub.9 1.500 N.sub.9 1.00000r.sub.10 .infin. d.sub.10 1.500 N.sub.10 1.00000r.sub.11 -267.072 d.sub.11 1.900 N.sub.11 1.77250 .nu..sub.11 49.8r.sub.12 -17.205 d.sub.12 0.100 N.sub.12 1.00000r.sub.13 8.284 d.sub.13 3.300 N.sub.13 1.77250 .nu..sub.13 49.8r.sub.14 -95.924 d.sub.14 0.350 N.sub.14 1.00000r.sub.15 -30.680 d.sub.15 3.500 N.sub.15 1.80518 .nu..sub.15 25.4r.sub.16 6.119 d.sub.16 0.100 N.sub.16 1.00000r.sub.17 15.508 d.sub.17 2.600 N.sub.17 1.78831 .nu..sub.17 47.3r.sub.18 -21.578 d.sub.18 1.500 N.sub.18 1.00000r.sub.19 .infin. d.sub.19 8.500 N.sub.19 1.51680 .nu..sub.19 64.1r.sub.20 .infin.d4 = 13.359-8.236-1.000 d9 = 1.500-8.319 -12.310______________________________________

In the first to fifteenth embodiments, the first lens unit and the second lens unit are shiftable along the optical axis in the zooming operation, while the third lens unit is stationary in the zooming operation. In the first to eighth embodiments, the third lens unit consists of, from the object side, a positive lens element whose object side surface has a stronger refractive power than its image side surface, a bi-concave lens element, a positive lens element whose image side surface has a stronger refractive power than its object side surface, and a positive lens element whose object side surface has a stronger refractive power than its image side surface. On the other hand, in the ninth to fifteenth embodiments, the third lens unit consists of, from the object side, a positive lens element whose image side surface has a stronger refractive power than its object side surface, a positive lens element whose object side surface has a stronger refractive power than its image side surface, a bi-concave lens whose image side surface has a stronger refractive power than its object side surface, and a bi-convex lens.

In the sixteenth to twenty-fifth embodiments, the first lens unit is stationary in the zooming operation, while the second lens unit and the third lens unit are shiftable in the zooming operation. In the sixteenth to twenty-first embodiments, the third lens unit consists of, from the object side, a positive lens element whose object side surface has a stronger refractive power than its image side surface, a bi-concave lens element, a positive lens element whose image side surface has a stronger refractive power than its object side surface, and a positive lens element whose object side surface has a stronger refractive power than its image side surface. On the other hand, in the twenty-second embodiment, the third lens unit consists of, from the object side, a positive lens element whose image side surface has a stronger refractive power than its object side surface, a positive lens element whose object side surface has a stronger refractive power than its image side surface, a bi-concave lens whose image side surface has a stronger refractive power than its object side surface, and a bi-convex lens.

In the twenty-sixth to thirty-third embodiments, the second lens unit consists of, from the object side, a negative lens element whose image side surface has a stronger refractive power than its object side surface, and a negative lens component in which a negative lens element and a positive lens element are cemented to each other. In the twenty-sixth to twenty-eighth embodiments, the first lens unit is stationary in the zooming operation, while the second and third lens units are shiftable in the zooming operation. On the other hand, in the twenty-ninth to thirty-third embodiments, the first and second lens units are shiftable in the zooming operation, while the third lens unit is stationary in the zooming operation.

In the above embodiments so the zoom lens system with the focusing operation, the embodiments 1, 4, 5, 6, 7, 15, 17, 18 and 21 each relate to a case of focusing method that the first lens unit (I) thereof serves as a focusing lens unit, as well as the embodiments 10, 11, 13, 16, 23, 24 and 25 each relate to another case of focusing method that the third lens unit (III) thereof serves as a focusing lens unit.

As can be readily appreciated, it is possible to deviate from the above embodiments of the present invention and, as will be readily understood by those skilled in the optical art, the invention is capable of many modifications and improvements within the scope and spirit thereof. Accordingly, it will be understood that the invention is not to be limited by these specific embodiments, but only by the scope and spirit of the appended claims.

Claims

1. A zoom lens system consisting, from the object side to the image side:

a first lens unit having a positive refractive power and being fixed on an optical axis of the lens system in a zooming mode of operation;

a second lens unit having a negative refractive power and being shiftable along the optical axis in the zooming mode of operation; and

a third lens unit having a positive refractive power and being shiftable along the optical axis in both the zooming operation and a focusing operation.

2. A zoom lens system as claimed in claim 1, wherein the first lens unit consists of, from the object side to the image side, a negative meniscus lens element having an object side surface convex to the object side and a positive lens element whose object side surface has a stronger refractive power than its image side surface, and the second lens unit consists of, from the object side to the image side, a negative lens element whose image side surface has a stronger refractive power than its object side surface and a positive lens element.

3. A zoom lens system consisting of, from the object side to the image side:

a first lens unit of a positive refractive power, consisting of, from the object side to the image side, a negative meniscus lens element having an object side surface convex to the object side and a positive lens element whose object side surface has a stronger refractive power than its image side surface;

a second lens unit of a negative refractive power consisting of, from the object side to the image side, a negative lens element whose image side surface has a stronger refractive power than its object side surface and a positive lens element, and

a third lens unit of a positive refractive power, wherein the second lens unit and one of the first and third lens units are shiftable along the optical axis of the lens system of the zooming operation, while another thereof is stationary on the optical axis in the zooming operation.