Early Photographic Critical Point Synchronization System and Method

• US 20120207459A1
• Filed: 08/12/2011
• Published: 08/16/2012
• Est. Priority Date: 02/12/2009
• Status: Active Grant

• Current Assignee: LAB Partners Associates Incorporated
• Original Assignee: LAB Partners Associates Incorporated
• Inventors: Clark, James E.
• Granted Patent: US 8,705,950 B2
• Time in Patent Office: Days
• US Class Current: 396/180
• CPC Class Codes: G03B 15/05 Combinations of cameras with electronic flash apparatus; Electronic flash units
• CPC Class Codes: G03B 2215/05 Combinations of cameras with electronic flash units
• CPC Class Codes: G03B 9/40 Double plate

Abstract

A system and method for synchronizing a photographic lighting device to image acquisition by a camera such that initiation of light emission of the photographic lighting device occurs after the first shutter blade of the camera begins to expose an image acquisition sensor of the camera to light and before X-sync associated with the first shutter blade stopping movement.

Claims

1. A method for synchronizing a photographic lighting device to image acquisition by a camera, the method comprising:

associating a photographic lighting device having a light emission profile with an initial critical point and a terminal critical point with the camera; and

initiating light emission from the photographic lighting device prior to a first shutter blade of the camera stopping movement such that the initial critical point occurs at a point in time after about 1 millisecond before the first shutter blade moves to a position that no longer obstructs light to an imaging portion of a sensor of the camera.

2. A method according to claim 1, wherein the initiating light emission occurs such that the initial critical point occurs at a point in time after about 500 microseconds before the first shutter blade moves to a position that no longer obstructs light to the imaging portion of the sensor.

3. A method according to claim 1, wherein the initiating light emission occurs such that the initial critical point occurs at a point in time after about 250 microseconds before the first shutter blade moves to a position that no longer obstructs light to the imaging portion of the sensor.

4. A method according to claim 1, wherein the initiating light emission occurs such that the initial critical point occurs at a point in time after the first shutter blade moves to a position that no longer obstructs light to the imaging portion of the sensor.

5. A method according to claim 1, wherein the initiating light emission occurs such that the initial critical point occurs at about the time the first shutter blade moves to a position that no longer obstructs light to the imaging portion of the sensor.

6. A method according to claim 1, wherein the initiating light emission occurs such that the initial critical point occurs before the first shutter blade stops movement.

7. A method according to claim 1, wherein the initiating light emission occurs such that the terminal critical point occurs before about 500 microseconds after a second shutter blade of the camera moves to a point where the second shutter blade starts to obstruct light from passing to the imaging portion of the sensor.

8. A method according to claim 1, wherein the initiating light emission occurs such that the terminal critical point occurs before about 250 microseconds after a second shutter blade of the camera moves to a point where the second shutter blade starts to obstruct light from passing to the imaging portion of the sensor.

9. A method according to claim 1, wherein the initiating light emission occurs such that the terminal critical point occurs at about the time that the second shutter blade starts to obstruct light from passing to the imaging portion of the sensor

10. A method according to claim 1, wherein the initiating light emission occurs such that the terminal critical point occurs before the time that the second shutter blade starts to obstruct light from passing to the imaging portion of the sensor

11. A method according to claim 1, further comprising:

identifying a camera predictor event and/or signal that occurs prior to the first shutter blade of the camera moving to a point that allows light to pass to the imaging portion of the sensor, the predictor event and/or signal not being an event or signal for instructing the initiation of light emission from a photographic lighting device, the predictor event and/or signal occurring prior to a normal flash initiation event or signal intended to instruct the light emission of the photographic lighting device; and

based upon the occurrence of the predictor event and/or signal, communicating to the photographic lighting device an instruction for the initiating light emission of the photographic lighting device.

12. A method according to claim 11, wherein the camera predictor event and/or signal is a serial data communication of the camera.

13. A method according to claim 12, wherein the serial data communication is a power set command.

14. A method according to claim 11, wherein the camera predictor event and/or signal is the initiation of a shutter magnet release signal.

15. A method according to claim 11, wherein the camera predictor event and/or signal is the initiation of an FP-synch signal and the initiating light emission does not include an FP-type flash emission.

16. A method according to claim 11, wherein the communicating includes delivering the instruction internal to the camera to an internal lighting device.

17. A method according to claim 11, wherein the communicating includes delivering the instruction via a hot shoe connector of the camera to the photographic lighting device, the photographic lighting device being positioned in the hot shoe connector.

18. A method according to claim 11, wherein the communicating includes wirelessly transmitting the instruction to the photographic lighting device.

19. A method according to claim 18, wherein the wirelessly transmitting includes a radio frequency transmission.

20. A method according to claim 18, wherein the instruction is wirelessly transmitted prior to the first shutter blade moving to a position that no longer obstructs light to the imaging portion of the sensor.

21. A method according to claim 18, wherein the instruction is received by a wireless communications receiver associated with the photographic lighting device prior to the first shutter blade moving to a position that no longer obstructs light to the imaging portion of the sensor.

22. A method according to claim 18, wherein the instruction is wirelessly transmitted prior to the occurrence of the normal flash initiation event or signal.

23. A method according to claim 18, wherein the instruction is received by a wireless communications receiver associated with the photographic lighting device prior to the occurrence of the normal flash initiation event or signal.

24. A method according to claim 11, wherein the initiating light emission occurs at a time delayed from completion of the communicating the instruction.

25. A method according to claim 24, wherein the instruction includes a delay factor.

26. A method according to claim 24, wherein the instruction includes a precalculated time for the initiating light emission.

27. A method according to claim 11, wherein the identifying includes detecting the predictor event and/or signal external to the camera.

28. A method according to claim 27, wherein the detecting occurs via a hot shoe connector of the camera.

29. A method according to claim 1, further comprising:

detecting a predictor signal and/or event;

determining an amount of time from the occurrence of the predictor signal and/or event until a desired time for the initiation of light emission of the photographic lighting device; and

transmitting to the photographic lighting device an instruction for the initiating light emission of the photographic lighting device at the desired time.

30. A method according to claim 29, wherein the detecting a predictor signal and/or event includes identifying the occurrence of an FP-sync signal of the camera.

31. A method according to claim 29, wherein the detecting a predictor signal and/or event includes identifying the occurrence of a power set command of the camera.

32. A method according to claim 29, wherein the detecting a predictor signal and/or event includes identifying the occurrence of a drop in voltage of a clock signal of the camera, the drop in voltage occurring after triggering of image acquisition and prior to the first shutter blade stopping movement.

33. A method according to claim 29, wherein the determining an amount of time includes utilization of a time value determined using a calibration that includes:

initiating an image acquisition sequence;

determining a start of movement of a second shutter blade;

using the shutter speed of the image acquisition, the shutter blade travel time for the camera, the time from the occurrence of the predictor signal and/or event to the start of movement of the second shutter blade to determine the time from the predictor signal and/or event to the stopping of movement of the first shutter blade.

34. A method according to claim 33, wherein the using step includes:

determining the time from the stopping of movement of the first shutter blade to the start of movement of the second shutter blade utilizing the shutter speed and the shutter blade travel time for the camera;

determining the time from the predictor signal and/or event to the stopping of movement of the first shutter blade utilizing the time from the occurrence of the predictor signal and/or event to the start of movement of the second shutter blade and the time from the stopping of movement of the first shutter blade to the start of movement of the second shutter blade

35. A method according to claim 29, wherein the determining an amount of time includes utilization of a time value determined using a calibration that includes:

initiating an image acquisition sequence;

analyzing the resultant image; and

modifying an adjustment factor that impacts the value of a delay factor of the instruction.

36. A system for synchronizing a photographic lighting device to image acquisition by a camera, the system comprising:

a means for associating a photographic lighting device having a light emission profile with an initial critical point and a terminal critical point with the camera; and

a means for initiating light emission from the photographic lighting device prior to a first shutter blade of the camera stopping movement such that the initial critical point occurs at a point in time after about 1 millisecond before the first shutter blade moves to a position that no longer obstructs light to an imaging portion of a sensor of the camera.

37. A system for synchronizing a photographic lighting device to image acquisition by a camera, the system comprising:

a connection to a camera circuitry providing access to a camera predictor signal;

a memory including information related to instructions for initiating light emission prior to a first shutter blade of the camera stopping movement such that the initial critical point occurs at a point in time after about 1 millisecond before the first shutter blade moves to a position that no longer obstructs light to an imaging portion of a sensor of the camera;

a processor element configured to use the information and the camera predictor signal to generate a lighting emission initiation signal; and

a connection to the photographic lighting device in communication with the processing element for communicating the lighting emission initiation signal to the photographic lighting device.