Patent Application
20080050110
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawings, in which:
The FIGURE is a flow chart of a method for adjusting a mechanical shutter (when the exposure time of the mechanical shutter is less than the control time of the mechanical shutter) of the present invention.
Referring to the FIGURE, the present invention provides a method for adjusting a mechanical shutter when an exposure time of the mechanical shutter is less than a control time of the mechanical shutter. The steps of the method comprise: measuring a raw image of an initial photo to obtain a standard brightness value, after the initial photo with a predetermined correct luminance is captured in a high luminance environment (S100). The high luminance environment has a brightness value between LV (Light Value) 15 and LV 16, and the predetermined correct luminance is 128 LM (lumen).
Moreover, the method further comprises: fixing some parameters that are changed easily when taking a picture, after auto exposure (AE) is stable (S102). In addition, the AE is a built-in automatic diaphragm control program. Because a camera can automatically adjust a size of a diaphragm of the camera according to different brightness, a user only needs to aim at an object when taking a picture. Furthermore, the parameters can be exposure time and auto gain control (AGC). The AGC is started when the camera senses the brightness is insufficient to increase a light level of a photo.
In addition, the method further comprises: adjusting the mechanical shutter's trigger point (S104); taking a picture for obtaining another photo and measuring a raw image of the another photo for obtaining a testing brightness value (S106); determining whether the testing brightness value and the standard brightness value are the same (S108); and if the testing brightness value and the standard brightness value are the same, determining that the trigger point is a real trigger point of the mechanical shutter (S110).
Furthermore, if the testing brightness value and the standard brightness value are different, repeating the steps from S104 to S108 until the testing brightness value and the standard brightness value are the same for obtaining the real trigger point of the mechanical shutter. In other words, if the testing brightness value and the standard brightness value are different, proceeding with the steps of adjusting the mechanical shutter's trigger point, taking a picture for obtaining another photo and measuring a raw image of the another photo for obtaining a testing brightness value and comparing whether the testing brightness value and the standard brightness value are the same. Hence, the steps of adjusting the trigger point, obtaining a testing brightness value, and comparing the testing brightness value with the standard brightness value are repeated until the testing brightness value and the standard brightness value are the same.
The method of the present invention uses LV 15 as brightness standard, so that an adjusted brightness value is correct in high brightness. Hence, a user can obtain pictures with correct brightness in a bright environment (above LV 15). In other words, insufficient exposure or overexposure does not happen in high brightness.
Although the present invention has been described with reference to the preferred best molds thereof, it will be understood that the invention is not limited to the details thereof. Various substitutions and modifications have been suggested in the foregoing description, and others will occur to those of ordinary skill in the art. Therefore, all such substitutions and modifications are intended to be embraced within the scope of the invention as defined in the appended claims.
