This disclosure relates to flash control in camera systems, and in particular to methods and apparatus for managing flash operations of a non-wireless photographic device with a wireless camera system.
It has been long recognized that communication methods other than by means of directly wired connections have utility and offer advantages in many settings. In a camera system, for example, optical communication, usually in the form of pulses of IR or visible light, enable photographic devices of the camera system to communicate and synchronize operation, without the use of cables or other means of directly connecting the devices to each other. In a standard example, a camera may instruct a remote flash unit to emit light for a pre-flash operation and/or during image acquisition by the camera, by means of operational commands encoded in sequences of optical pulses emitted by the camera and received by the flash unit.
Although it has become conventional for photographic devices to employ optical communication, this approach has limitations, however, such as in shooting conditions in which the ambient lighting, reflective surfaces, weather conditions, and so forth, may interfere with reliable receipt of pulsed optical data. As such, wireless communication systems, i.e. communication systems using radio waves, have been developed for use with conventional camera systems that employ optical means of communication. For example, methods, systems, and devices employing wireless communication for conventional camera systems, such as to establish, facilitate, and maintain wireless communication among various photographic devices of a camera system, to prepare and activate flash units by radio, and so forth, are disclosed in Applicant's co-pending U.S. Patent Application Pub. Nos. US2009012975, US20100008658, US20100124412, US20100158494, and US20100209089, the complete disclosures of which are hereby incorporated by reference. One or more of the aforementioned publications disclose various examples of external wireless communication devices that may be used to retrofit conventional (i.e. non-wireless) photographic devices with wireless functionality.
Recently, photographic equipment has been developed that integrates wireless functionality into photographic devices. The term “wireless-enabled” is used herein to refer to a photographic device, such as a camera, a flash unit, a light metering device, and so forth, that incorporates wireless reception and/or transmission means (and to distinguish, the term “non-wireless,” as used herein, refers to photographic devices that do not incorporate wireless functionality). For example, U.S. Patent Application Pub. No. 20100202767 of Shirakawa discloses a wireless camera system that includes a camera and a flash unit both having built-in wireless capability. In the Shirakawa camera system, the wireless-enabled camera wirelessly transmits a sequence of emitting command packets to the wireless-enabled flash unit, each of which include timing information for a subsequent operation of the camera that will take place at a predetermined time. The timing information in each emitting command packet is different depending on its place in the sequence. Once any of the command packets are received by the wireless-enabled flash unit, circuitry in the flash unit reads the timing information and carries out an emitting operation that is synchronized with the camera operation.
A substantial drawback to the use of wireless-enabled photographic equipment is that many existing photographic devices are non-wireless, and thus may not be compatible with wireless-enabled photographic devices, such as those disclosed in Shirakawa.
The methods and apparatus disclosed herein may facilitate synchronization of an operation by a non-wireless photographic device, such as the emission of light by a non-wireless flash device, with that of an operation by a wireless-enabled photographic device, such as an image acquisition operation by a wireless-enabled camera, and/or may otherwise integrate a non-wireless photographic device into a wireless camera system that includes one or more wireless-enabled photographic devices.
In one illustrative method in accordance with the present disclosure, emission of light from a non-wireless flash device may be synchronized with the performance of a selected photographic operation (such as a camera operation, for example, a pre-flash operation, image acquisition, and so forth, or an operation by another photographic device) by a wireless-enabled photographic device that is part of a wireless camera system. Such a method may include receiving a signal wirelessly transmitted by a photographic device (such as a wireless-enabled camera) of the wireless camera system, identifying the received signal as one that characteristically precedes the performance of the selected photographic operation by a predetermined time interval, and determining, from the identified signal, the predetermined time interval. The method may then include transmitting an emission synchronization signal perceptible to the non-wireless flash device so that the responsive emission of light therefrom is synchronized with performance of the selected photographic operation. Depending upon the setup of the wireless camera system, the wireless-enabled photographic device that transmits the received signal may be the same photographic device that performs the selected photographic operation, for example in a wireless camera system in which a wireless-enabled camera transmits flash instructions to wireless-enabled flash devices of the system to synchronize flash operations with various operations of the camera.
In such a method, the identified signal may be a flash instruction such as an emission instruction signal, and further may be one of a sequence of emission instruction signals wirelessly transmitted by the photographic device, each of which may contain different timing information for the performance of a selected photographic operation, depending on its place in the sequence. Accordingly, in such a method, the predetermined time may be determined from the timing information in the identified signal; this method may optionally include subsequently ignoring other emission instruction signals in the sequence. In a variant of such a method, the predetermined time interval may instead be determined using an observed time interval from a prior operation of the wireless camera system, such as one in which a prior iteration of the identified signal preceded the subsequent performance of the selected photographic operation.
Optionally, the identified signal may include information such as an emission output level, in which case transmitting the emission synchronization signal may include transmitting emission output level information corresponding to or otherwise based on the emission output level in the identified signal.
The illustrative method optionally may be interactive, such as by further including a step of wirelessly transmitting a signal back to the photographic device as if it was sent from the non-wireless flash device, and/or by otherwise establishing a communication link with the photographic device such that the photographic device thereafter wirelessly communicates with the non-wireless flash device as if it was another wireless-enabled photographic device of the wireless camera system, such as a wireless-enabled flash device.
The illustrative method may further include transmitting the emission synchronization signal to the non-wireless flash device in any manner suitable to the non-wireless flash device, such as by sending the emission synchronization signal optically, via an electrical connection, and so forth. Such a method may thus include initiating the transmission at a time sufficiently in advance of the performance of the photographic operation so as to complete transmission and allow the non-wireless flash device any necessary time to emit light synchronized with performance of the photographic operation.
In another illustrative method in accordance with the present disclosure, a non-wireless photographic device (such as a non-wireless flash device, or otherwise) may be integrated into a wireless camera system in which a master device of the wireless camera system (such as a wireless-enabled camera, a remote control device, and so forth) wirelessly transmits at least one signal in advance of a predetermined time at which a selected photographic operation according to the signal is to be initiated by a photographic device of the wireless camera system (such as image acquisition by a wireless-enabled camera, a pre-flash operation by such a camera, emission of light by a wireless-enabled flash device, and so forth). Such a method may include receiving a signal wirelessly transmitted by the master device, determining the predetermined time at which the selected photographic operation is to be initiated by the photographic device of the wireless camera system from the received signal, calculating the amount of time to transmit a synchronization signal to the non-wireless photographic device that is perceptible to the non-wireless photographic device (such as a pulsed optical signal), and transmitting the synchronization signal at a time in advance of the predetermined time so that upon receipt of the synchronization signal, a photographic operation of the non-wireless photographic device (such as a flash emission of a non-wireless flash device, and so forth) responsive to the synchronization signal will be initiated at the predetermined time.
The aforementioned illustrative methods may be accomplished using various suitable components and devices as discussed herein. An illustrative example configuration of such a component, constructed in accordance with aspects of the present disclosure, may be in the form of a wireless activation device suitable for use with a non-wireless photographic device (such as a non-wireless flash device) and may include a receiving component, a transmitting component, and functional circuitry. The receiving component of such a wireless activation device may be adapted to receive a radio signal transmitted by a master device of a wireless camera system a predetermined interval of time preceding the performance of a camera operation by a camera of the wireless camera system, whereas the transmitting component may be adapted to transmit an activation signal perceptible to the non-wireless photographic device and that is configured to activate a selected operation of the non-wireless photographic device. The circuitry of such a wireless activation device may be adapted to determine, from the radio signal, the predetermined interval of time, calculate therefrom a time suitable to transmit the activation signal such that the selected operation of the non-wireless photographic device will be synchronized with the performance of the camera operation, and cause the transmitting component to transmit the activation signal at the calculated time.
The concepts, features, methods, and component configurations briefly described above are clarified with reference to the accompanying drawings and detailed description below.
The present invention may be described herein in terms of illustrative methods that include various functional steps and processes. Such functional steps and processes may be realized by any number of hardware or software components configured to perform the respective functions and thereby achieve the various results described herein, which may represent various implementations of the present invention. Further, the illustrative methods and implementations thereof are disclosed by way of several examples, such as that may employ photographic equipment such as cameras, flash devices, and so forth, that may be used in a photographic studio setting. However, the invention is not restricted to use with such example settings and equipment, as numerous applications, variations, settings, and use with any image capturing (and accessory) equipment are possible and within the scope of this disclosure.
The wireless-enabled photographic devices of wireless camera system 102 may be configured as disclosed, for example, in U.S. Patent Application Pub. No. 20100202767 of Shirakawa, the complete disclosure of which is hereby incorporated by reference. For example, wireless-enabled camera 104 and wireless-enabled flash device 106 may each include, in addition to the various optical, mechanical, and electrical components to perform photographic imaging and/or flash emission, a wireless antenna operated by a wireless communication circuit, such that the wireless-enabled photographic devices may communicate via wireless communication signals, generally indicated at 108.
Photographic setup 100 is also shown to include a wireless activation device 110 and a non-wireless flash device 112, which may represent any suitable type of photographic lighting device capable of emitting photographic illumination, such as a studio monolight (for example, a Photogenic PL1250), an electronic flash unit (for example, a Canon Speedlite 430EX), and so forth. As noted above, non-wireless flash devices may be configured for communication with a master photographic device in various ways, the two main ways being via a direct electical connection, such as by means of a cord, cable, hotshoe connection, and so forth, and via optical communications. As such, although wireless activation device 110 is shown to be directly coupled to the flash device 112 via a cord 114, communication between wireless activation device 110 and flash device 112 may not require a direct connection.
As explained in further detail herein, wireless activation device 110 may be configured to receive wireless communications from, and/or otherwise wirelessly communicate with, a wireless-enabled photographic device of a wireless camera system, such as wireless-enabled camera 104 of wireless camera system 102, and thus facilitate integration of a non-wireless photographic device, such as non-wireless flash device 112, with the wireless camera system. In one example, the emission of light from non-wireless flash device 112 may be synchronized with image acquisition by wireless-enabled camera 104. In another example, wireless activation device 110 may establish a communication link between non-wireless flash device 112 and wireless-enabled camera 104, such that the wireless-enabled camera 104 transmits wireless communications to the wireless activation device 110 (which, in turn, may be transmitted to the non-wireless flash device 112) as if the wireless activation device 110 was a slave device, such as a wireless-enabled flash device, of the wireless camera system 102.
The example embodiment of wireless activation device 110 is also shown, in
The wireless activation device may further include a power source 218, such as an internal power source in the form of a battery 220, or may be externally powered, such as a conventional AC power cord, a USB cable, and so forth. Optionally, the wireless activation device may further include, or be configured to couple with, one or more memory components 222 configured to store data such as programming instructions, operational data, and so forth, such as an internal memory incorporated within or in communication with processing means 216, removable storage media, and so forth. Wireless activation device 110 is shown to commonly house all of the aforementioned components in a single, battery-powered unit, but the various functional components may, in other embodiments, be configured as desired to achieve the functionality of the device as described herein.
In a first illustrative example of using a wireless activation device, such as wireless activation device 110, with a wireless camera system, such as wireless camera system 102, a receiving component of the wireless activation device may begin receiving radio signals, such as those transmitted by wireless-enabled camera 104. One of the signals may be an emission instruction signal or other type of flash instruction transmitted by the camera 104 in advance of performing an image acquisition operation or a pre-flash operation, which includes timing information for the performance of the operation, such as the time interval following the signal after which the operation will occur. The processing means of the wireless activation device may recognize the received signal as an emission instruction signal, read the timing information for the camera operation in the signal, and calculate therefrom the correct timing to prompt the transmitting component to emit an activation signal perceptible to the non-wireless flash device, in turn causing the non-wireless flash device to carry out a desired operation, such as a flash emission, coincident with the camera operation.
U.S. Patent Application Pub. No. 20100202767 of Shirakawa discloses an example of a wireless camera system in which a wireless-enabled camera issues a sequence of wireless emitting instruction signals in advance of opening its shutter for image acquisition.
Of course, the example wireless camera system discussed above employs one example technique of transmitting signals—specifically, a sequence of emission instruction signals that each include timing information as part of the signal—prior to a photographic operation. Other wireless camera systems may not include a sequence of redundant emission instruction signals, and may instead transmit a single emission instruction signal that includes timing information, and still others may transmit one or more emission instruction signals that do not include timing information.
Moreover, an emission instruction signal is one example of a signal that may be transmitted by a master device of a wireless camera system that characteristically precedes the performance of a selected photographic operation by a predetermined time interval. Some wireless camera systems may employ other wireless signals that characteristically precede a selected operation, which may be recognized as such in a variety of manners, such as by observing the wireless communications that are transmitted prior to a variety of photographic operations and recording such communications in a memory accessible, for example, to a wireless activation device. Thus, when a wireless activation device receives such a signal, the predetermined time interval may be determined by recognizing the signal, and use an observed time interval from a prior operation of the camera system. Such signals, and corresponding time intervals, may be characteristic of and/or proprietary to certain camera systems and may thus differ among systems or manufacturers, and as such may be preprogrammed into memory to be retrieved according to the wireless camera system in use, and so forth.
A second illustrative example of using a wireless activation device, such as wireless activation device 110, with a wireless camera system, involves the use of such a different type of wireless signal. In the second illustrative example, a wireless signal indicating that a camera shutter button has been half- or fully-pressed by a user operating the camera may be transmitted by the camera, and received by the wireless activation device 110. Such a signal may characteristically precede a subsequent flash instruction for a flash device to emit a pre-flash emission, and/or the performance of a light measurement operation by the camera, by a predetermined amount of time.
As noted above, the delay between transmission of the SW2 signal and the transmission of the subsequent pre-emitting commands may be a known characteristic of the camera system in use, or may be recorded from a previously observed photographic operation thereof. As such, upon the receipt of a SW2 signal by a wireless activation device, the processing means thereof may recognize the received signal as such, and determine the predetermined time interval until the performance of a subsequent camera or flash operation, even though the SW2 signal itself may not contain any timing information, such by using an observed time interval. The observed time interval may be one that was used in a prior operation of the camera system that the wireless activation device observed and recorded, or that has been preprogrammed into memory accessible to the wireless activation device, and so forth. As in the first illustrative example, the processing means of the wireless activation device may then calculate the correct timing to prompt the transmitting component to emit an activation signal perceptible to a non-wireless flash device, in turn causing the non-wireless flash device to carry out a desired operation, such as a pre-flash emission, coincident with the camera or flash operation.
In one or both of the illustrative examples discussed above, the time interval between the receipt of a signal from a photographic device and the performance of a corresponding, subsequent photographic operation may exceed the amount of time needed, such as by the wireless activation device, for formatting and transmitting an emission synchronization signal to a non-wireless flash device, and any time required by the non-wireless flash device to prepare for the emission. In one non-limiting example, if the non-wireless flash device is charged and prepared to emit a pre-flash (such as following a prior signal from the wireless activation device), the wireless activation device may only need a short amount of time, such as 1 millisecond, to produce and transmit an appropriate signal for the non-wireless flash device, such as a pulsed light signal. In other examples, such as that may involve a flash instruction such as an emission instruction signal, the emission instruction signal may precede image acquisition by the camera by 1 millisecond, in which case the wireless activation device may initiate the production of a corresponding pulsed light signal for the non-wireless flash device upon (or even while) receiving the emission instruction signal. However, in other examples, such as that may involve a SW2 or similar wireless signal, such a signal may precede the subsequent camera operation by an interval greater than 1 millisecond, such as several milliseconds, or even several tens or hundreds of milliseconds. Accordingly, once the time interval is determined from such a signal, the wireless activation device may allow an appropriate portion of the time interval to elapse before transmitting the emission synchronization signal to the non-wireless flash device, to synchronize the emission by the flash device with the camera operation.
Similarly, processing means of a wireless activation device may calculate the proper portion of the time interval to elapse before transmitting a synchronization signal to the non-wireless flash device for any manner of transmitting the synchronization signal, and based on any received wireless signal that may be recognized as preceding a selected photographic operation by a predetermined amount of time. Such signals may include one of those indicated on the “camera transmission data” lines of the example timing charts shown in
Although not required to all embodiments, some methods of synchronizing an operation of a non-wireless flash device with a selected photographic operation by a wireless-enabled photographic device that is part of a wireless camera system may include wirelessly transmitting a signal to a wireless-enabled photographic device (such as a camera or other master device) of the wireless camera system, which is configured to be interpreted by the photographic device as if it was sent by a wireless-enabled flash device (or other slave device) of the wireless camera system. For example, with reference to the example wireless camera system 102 illustrated in
Optionally, a non-wireless flash device may be instructed, such as by means of a wireless activation device, to set a light emission output level to a desired level, such as a level that would characteristically be emitted by a wireless-enabled flash device of the wireless camera system with which the non-wireless flash device is being used. Such a light emission output level may be encoded in a flash instruction received from a photographic device of the wireless camera system, such as an emission instruction signal, and/or another signal such as a LIGHT AMOUNT SETTING signal (such as indicated in
In the foregoing disclosure, the present invention has been described with reference to specific illustrative embodiments, methods, processes, and other examples, and selected variants thereof. It will be apparent to those skilled in the art that various modifications and changes may be made, however, without departing from the scope of the present invention as set forth in the claims. The specification and drawings are provided for illustrative purposes, rather than to restrict or limit any aspect of the scope of the disclosure. The present invention is intended to embrace all such alternatives, modifications and variances that fall within the scope of the appended claims.
For example, the steps, actions, or events recited in any of the methods or processes disclosed and/or claimed herein may be executed in any order and may not be limited to the specific order presented. Additionally, components and/or elements presented and/or claimed in any apparatus, device, component herein may be assembled or otherwise operationally configured in a variety of permutations and accordingly may not be limited to the specific configuration(s) presented.
Further, benefits, other advantages, and solutions to problems or challenges may be described herein with regard to particular embodiments, however, any such benefit, advantage, solution, or any element that may enhance or cause any particular benefit, advantage, or solution to occur are not to be construed as critical, required, or essential features or components of the invention, nor should the claims be construed as exclusively addressing such benefits, advantages, or solutions.
This application claims the benefit of U.S. Provisional Application No. 61/374,600, filed Aug. 17, 2010, the entire disclosure of which is incorporated herein by reference for all purposes.
Number | Date | Country | |
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61374600 | Aug 2010 | US |