APPARATUS AND METHOD FOR RECORDING A SCENE USING TWO ALTERNATING LIGHTING SETUPS SO AS TO CONCURRENTLY RECORD MOTION PICTURE FOOTAGE FOR EACH LIGHTING SETUP

Abstract

An apparatus and method for recording a scene using two lighting setups in alternation so as to concurrently record motion picture footage of the scene for each lighting setup, the footage for the two lighting setups having minimized motion offset. The apparatus includes: a plurality of light sources, a controller to define two lighting setups using the plurality of light sources, and to actuate the lighting setups in alternation, a camera to capture a sequence of frames showing the scene illuminated by one of the two lighting setups in alternation, and optionally a processing module to process the sequence of frames to generate two clips of footage of the scene, each corresponding to a lighting setup. The timing of actuation of the lighting setups relative to the frame boundaries avoids the need to use optical flow algorithms to remove motion artifacts, and the need for a specialized high speed camera.

Claims

1. An apparatus for recording a scene using two alternating lighting setups so as to concurrently record motion picture footage of the same scene for each lighting setup of the scene, the apparatus comprising: a plurality of light sources, each light source configured to illuminate the scene; a controller configured to: enable a user to define two lighting setups using at least two of the plurality of light sources, and actuate the two lighting setups in alternation in accordance with a timing signal; and a camera configured to capture a sequence of frames, each one of the frames showing the scene illuminated by one of the two lighting setups in alternation.

2. The apparatus of claim 1, further comprising: a processing module configured to process the sequence of frames so as to generate two separate clips of footage of the scene, each clip corresponding to one of the lighting setups.

3. The apparatus of claim 1, wherein the controller is configured to: actuate the two lighting setups in alternation in accordance with a timing signal such that a first lighting setup is actuated just prior to an end of a frame, and a second lighting setup is actuated just after a beginning of an immediately subsequent frame.

4. The apparatus of claim 1, wherein a time interval starting upon actuation of the first lighting setup and ending upon the second lighting setup going dark after actuation does not exceed 17 microseconds.

5. The apparatus of claim 1, wherein the timing signal is derived from the camera in accordance with a frame rate of the camera.

6. The apparatus of claim 1, wherein the timing signal is derived from a time clock configured to provide a clock signal.

7. The apparatus of claim 1, wherein the controller is also configured to: enable a user to define the two lighting setups so as to include at least one camera parameter that can change from frame to frame; and alternatingly actuate the at least one camera parameter for each of the two lighting setups in accordance with the timing signal.

8. The apparatus of claim 7, wherein the at least one camera parameter can include at least one of: sensitivity (ISO); aperture; ND (neutral density filter); and shutter angle.

9. An apparatus for recording a scene using two alternating lighting setups so as to concurrently produce motion picture footage of the same scene for each lighting setup of the scene, the motion picture footage having minimized motion offset with respect to each other, the apparatus comprising: a plurality of light sources, each light source configured to illuminate the scene; a first lighting setup selected from the plurality of light sources; a second lighting setup selected from the plurality of light sources, the second lighting setup being different from the first lighting setup; a camera configured to capture a sequence of frames, each one of the frames showing the scene illuminated by first lighting setup or by the second lighting setup, in alternating relationship, the camera also configured to provide a frame boundary signal at a beginning and at an end of each frame; and a controller configured to actuate the two lighting setups in alternation in accordance with the frame boundary signal such that a first lighting setup is actuated just prior to an end of a frame, and a second lighting setup is actuated just after a beginning of an immediately following frame.

10. The apparatus of claim 9, further comprising: a processing module configured to process the sequence of frames so as to generate two separate clips of footage of the scene, each clip corresponding to one of the lighting setups.

11. The apparatus of claim 9, wherein a time interval starting upon actuation of the first lighting setup and ending upon the second lighting setup going dark after actuation does not exceed 17 milliseconds.

12. The apparatus of claim 9, wherein the controller is also configured to: enable a user to define the two lighting setups so as to include at least one camera parameter that can change from frame to frame; and alternatingly actuate the at least one camera parameter for each of the two lighting setups in accordance with a timing signal.

13. The apparatus of claim 12, wherein the at least one camera parameter can include at least one of: sensitivity (ISO); aperture; ND (neutral density filter); and shutter angle.

14. A method for recording a scene using two alternating lighting setups so as to concurrently produce motion picture footage of the scene for each lighting setup of the scene, the motion picture footage having minimized motion offset with respect to each other, the method comprising: selecting a plurality of light sources, each light source configured to illuminate the scene; selecting a first lighting setup from the plurality of light sources; selecting a second lighting setup from the plurality of light sources, the second lighting setup selected being different from the first lighting setup; actuating the first lighting setup and the second lighting setup in alternation in accordance with a timing signal, including actuating the first lighting setup just prior to an end of a frame, and actuating the second lighting setup just after a beginning of an immediately subsequent frame; and capturing a sequence of frames using a camera, each one of the frames showing the scene illuminated by one of the two lighting setups in alternation.

15. The method of claim 14, further including: processing the sequence of frames so as to generate two separate clips of footage of the scene, each clip corresponding to one of the lighting setups.

16. The method of claim 14, wherein a time interval starting upon actuation of the first lighting setup and ending upon the second lighting setup going dark after actuation does not exceed 17 milliseconds.

17. The method of claim 14, wherein the timing signal is derived from the camera in accordance with a frame rate of the camera.

18. The method of claim 14, wherein the timing signal is derived from a time clock configured to provide a clock signal.

19. The method of claim 14, wherein: selecting a first lighting setup from the plurality of light sources includes selecting at least one camera parameter that can change from frame to frame; and selecting a second lighting setup from the plurality of light sources, the second lighting setup selected being different from the first lighting setup, includes selecting at least one camera parameter that changes from frame to frame in alternating relationship in accordance with the timing signal.

20. The method of claim 19, wherein the at least one camera parameter can include at least one of: sensitivity (ISO); aperture; ND (neutral density filter); and shutter angle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Many additional features and advantages will become apparent to those skilled in the art upon reading the following description, when considered in conjunction with the accompanying drawings, wherein:

[0039] FIG. 1A is a schematic diagram of a scene illuminated alternately by one of two lighting setups, with minimal motion offset between frames corresponding to the two lighting setups.

[0040] FIG. 1B is a schematic diagram of a sequence of frames recorded at a standard cinematic frame rate, showing the odd frames, the even frames, and a short-duration lighting interval that is suitable for a standard-speed motion of the filmed scene.

[0041] FIG. 1C is a schematic diagram of a sequence of frames recorded at a standard cinematic frame rate, showing the odd frames, the even frames, and an long-duration lighting interval that is that is suitable for a slow-speed motion of the filmed scene.

[0042] FIG. 1D is a schematic diagram of a sequence of frames recorded at a rapid cinematic frame rate, showing the odd frames, the even frames, and a short-duration lighting interval that is suitable for a standard-speed motion of the filmed scene.

[0043] FIG. 1E is a schematic diagram of a sequence of frames recorded at a rapid cinematic frame rate, showing the odd frames, the even frames, and an long-duration lighting interval that is suitable for a slow-speed motion of the filmed scene.

[0044] FIG. 2 is a schematic diagram showing how to process footage of a scene illuminated sequentially by two lighting setups so as to produce two respective pieces of footage of the scene each showing the scene illuminated by one of the two lighting setups.

[0045] FIG. 3 is a schematic diagram of a top view of a scene lit with a continuous light source and two light sources, the light sources being controlled by a controller that receives timing signals from a camera recording the scene so as to provide two lighting setups.

[0046] FIG. 4 is a schematic diagram of a top view of a scene lit with four light sources, the light sources being controlled by a controller that receives timing signals from a camera recording the scene so as to provide two lighting setups, the first lighting setup having two light sources and the second lighting setup having two light sources.

[0047] FIG. 5 is a schematic diagram of a top view of a scene lit with four light sources, the light sources being controlled by a controller that receives timing signals from a camera recording the scene so as to provide two lighting setups, the first lighting setup having three light sources and the second lighting setup having one light source.

[0048] FIG. 6 is a schematic diagram of a top view of a scene lit with four light sources, the light sources being controlled by a controller that receives timing signals from a camera recording the scene so as to provide two lighting setups, the first lighting setup having one light source and the second lighting setup having three light sources.

[0049] FIG. 7 is a flow chart of a method for recording a scene using two alternating lighting setups so as to concurrently produce motion picture footage of the scene for each lighting setup of the scene, each motion picture footage having minimized time offset with respect to each other.

DETAILED DESCRIPTION

[0050] With reference to FIG. 1A, a schematic diagram of a top view of a scene lit with four light sources is shown of an apparatus for recording a scene using multiple lighting setups 100. The apparatus for recording a scene using multiple lighting setups 100 includes a controller 102 in communication with a camera 106 configured to record a scene 104. The controller 102 is also in communication with lighting equipment consisting of: a light source 108, a light source 110, a light source 112, and a light source 114. The lighting is divided into two lighting setups: a first lighting setup 116, and a second lighting setup 118. A light source can be a strobe light, one or more LEDs, or other light source that can be switched on and off relatively rapidly.

[0051] Flash duration of a light source is commonly described by two numbers that are expressed in fractions of a second: [0052] t.1 is the length of time the light intensity is above 0.1 (10%) of the peak intensity [0053] t.5 is the length of time the light intensity is above 0.5 (50%) of the peak intensity For example, a single flash event might have a t.5 value of 1/1200 and t.1 of 1/450. These values determine the ability of a flash to freeze moving subjects in applications such as sports photography.

[0054] Individual strobe flashes typically last approximately 200 microseconds, i.e., 0.2 milliseconds, i.e., of a millisecond, but can be sustained for greater or lesser periods of time depending on the strobe's intended use.

[0055] Here are some time durations for comparison:

0.2 millisecondsduration of a typical strobe flash
1 millisecond (1 ms)duration of light for typical photo flash strobe.
2 milliseconds to 5 millisecondstypical response time in LCD computer monitors, especially high-end displays
8 milliseconds- 1/125 of a second, a standard camera shutter speed (125)
16.68 milliseconds (1/59.94 second)the amount of time one field lasts in 29.97 fps interlaced video (commonly but erroneously referred to as 30 fps)
33.367 millisecondsthe amount of time one frame lasts in 29.97 fps video (most common for NTSC-legacy formats)
41.667 millisecondsthe amount of time one frame lasts in 24 fps video (most common cinematic frame rate)
41.708 millisecondsthe amount of time one frame lasts in 23.976 fps video (cinematic frame rate for NTSC-legacy formats)
134 millisecondstime taken by light to travel around the Earth's equator
200 millisecondsthe time it takes the human brain to recognize emotion in facial expressions
300 to 400 millisecondsthe time for the human eye to blink
1000 millisecondsone second

[0056] The camera 106 records the action in scene 104 as a sequence frames 120. The camera can be a camera with a standard frame rate, or a relatively high speed camera. The sequence of frames 120 includes odd frames 122 and even frames 124. The scene 104 is alternately illuminated by the first lighting setup 116, and then the second lighting setup 118. The even frames 122 record the scene 104 illuminated by the first lighting setup 116, and the odd frames record the scene 104 illuminated by the second lighting setup 118. Lighting intervals 126 are shown to indicate the duration of the time interval between the illumination of the first lighting setup 116, and the illumination of the second lighting setup 118. The controller 102 controls the timing of the lighting intervals 126. The lighting intervals 126 are chosen such that the illumination from the first lighting setup 116 and the illumination from the second lighting setup 118 provide minimal motion offset between frames corresponding to the two lighting setups.

[0057] With reference to FIG. 1B, a schematic diagram is shown of the sequence of frames 120, recorded at a standard cinematic frame rate, and with a short-duration lighting interval 126 that is suitable for a standard-speed motion of the filmed scene 104. In some embodiments, a standard cinematic frame rate can be 30 Hz. As shown in FIG. 1A, the odd frames 122 correspond to illumination from the first lighting setup 116, and the even frames 124 correspond to illumination from the second lighting setup 118. An even-odd frame boundary 128 indicates the time when the end of an odd frame coincides with beginning of the adjacent even frame. The lighting interval 126 includes a leading interval 130 and a trailing interval 132, both of which combine to form the lighting interval 126. In preferred embodiments, the leading interval 130 and the trailing interval 132 are substantially equal in time duration. In this embodiment, the lighting interval 126 is short in duration, to substantially minimize visual artifacts (such as motion offset between frames corresponding to the two lighting setups) when post processing the sequence of frames 120, if standard-speed motion is present in the scene 104 (shown in FIG. 1A).

[0058] With reference to FIG. 1C, a schematic diagram is shown of the sequence of frames 120, recorded at a standard cinematic frame rate, and with a long-duration lighting interval 126 that is suitable for a slow-speed motion of the filmed scene 104. In some embodiments, a standard cinematic frame rate can be 30 Hz. The even-odd frame boundary 128 indicates the time when the end of an odd frame coincides with beginning of the adjacent even frame. The lighting interval 138 includes a leading interval 134 and a trailing interval 136, both of which sum to form the lighting interval 138. In preferred embodiments, the leading interval 134 and the trailing interval 136 are substantially equal in time duration. In this embodiment, the lighting interval 138 is long in duration, however, if only slow-speed motion is present in the scene 104 (shown in FIG. 1A), there will be no visual artifacts (such as motion offset between frames corresponding to the two lighting setups) when post processing the sequence of frames 120.

[0059] With reference to FIG. 1D, a schematic diagram is shown a sequence of frames 140, recorded at a fast cinematic frame rate, and with a short-duration lighting interval 148 that is suitable for a standard-speed motion of the filmed scene 104. In some embodiments, a fast cinematic frame rate can be 60 Hz. An even-odd frame boundary 142 indicates the time when the end of an odd frame coincides with beginning of the adjacent even frame. The lighting interval 148 includes a leading interval 144 and a trailing interval 146, both of which sum to form the lighting interval 148. In preferred embodiments, the leading interval 144 and the trailing interval 146 are substantially equal in time duration. In this embodiment, the lighting interval 148 is short in duration, to substantially minimize visual artifacts (such as motion offset between frames corresponding to the two lighting setups) when post processing the sequence of frames 140, if standard-speed motion is present in the scene 104 (shown in FIG. 1A).

[0060] With reference to FIG. 1E, a schematic diagram is shown of the sequence of frames 140, recorded at a fast cinematic frame rate, and with a long-duration lighting interval 154 that is suitable for a slow-speed motion of the filmed scene 104. In some embodiments, a fast cinematic frame rate can be 60 Hz. The even-odd frame boundary 142 indicates the time when the end of an odd frame coincides with beginning of the adjacent even frame. The lighting interval 154 includes a leading interval 150 and a trailing interval 152, both of which sum to form the lighting interval 154. In preferred embodiments, the leading interval 150 and the trailing interval 152 are substantially equal in time duration. In this embodiment, the lighting interval 154 is long in duration, however, if only slow-speed motion is present in the scene 104 (shown in FIG. 1A), there will be substantially no visual artifacts (such as motion offset between frames corresponding to the two lighting setups) when post processing the sequence of frames 140.

[0061] With reference to FIG. 2, a schematic diagram is shown including the sequence of frames 120 with individual frames numbered 1 through n, with n being an even number. The sequence of frames 120 produce two respective pieces of footage of the scene, each showing the scene illuminated by one of the two lighting setups: the first lighting setup 116, and the second lighting setup 118 (both shown in FIG. 1A). The odd-numbered frames of the sequence of frames 120 produce footage of an odd frame clip 202, and the even-numbered frames of the sequence of frames 120 produce footage of an even frame clip 204.

[0062] With reference to FIG. 3, a schematic diagram of a top view of a scene lit with two light sources is shown of an apparatus for recording a scene using multiple lighting setups 300. Included is the controller 102 in communication with the camera 106 configured to record the scene 104. In this embodiment, a continuous light source 302 provides constant illumination for the scene 104. In addition, a light source 304 and a light source 306 each provide short duration illumination for the scene 104. The lighting is divided into two lighting setups: a first lighting setup 308, and a second lighting setup 310.

[0063] With reference to FIG. 4, a schematic diagram of a top view of a scene lit with four light sources is shown of an apparatus for recording a scene using multiple lighting setups 400. Included is the controller 102 in communication with the camera 106 configured to record the scene 104. In this embodiment, a light source 402 and a light source 404 are included in a first lighting setup 410 to provide light for the scene 104. In addition, a light source 406 and a light source 408 are included in a second lighting setup 412 to provide light for the scene 104.

[0064] The controller 102 activates the first lighting setup 410 at a time within the odd-numbered frames of the sequence of frames 120 (shown in FIG. 1A), and the controller 102 activates the second lighting setup 412 within the even-numbered frames of the sequence of frames 120 (shown in FIG. 1A).

[0065] The first lighting setup 410 includes the light source 402 and the light source 404, both synchronized by the controller 102 to provide short duration illumination to the scene 104 at the same time, corresponding to the odd frames in the sequence of frames 120 (shown in FIG. 1A).

[0066] The second lighting setup 412 includes the light source 406 and the light source 408, both synchronized by the controller 102 to provide short duration illumination to the scene 104 at the same time, corresponding to the even frames in the sequence of frames 120 (shown in FIG. 1A).

[0067] With reference to FIG. 5, a schematic diagram of a top view of a scene lit with four light sources is shown of an apparatus for recording a scene using multiple lighting setups 400. Included is the controller 102 in communication with the camera 106 configured to record the scene 104. In this embodiment, the light source 402, the light source 404, and the light source 406 are included in a first lighting setup 502 to provide light for the scene 104. In addition, the light source 408 is included in a second lighting setup 504 to provide light for the scene 104.

[0068] The controller 102 activates the first lighting setup 502 at a time within the odd-numbered frames of the sequence of frames 120 (shown in FIG. 1A), and the controller 102 activates the second lighting setup 504 within the even-numbered frames of the sequence of frames 120 (shown in FIG. 1A).

[0069] The first lighting setup 502 includes the light source 402, the light source 404, and the light source 406, all synchronized by the controller 102 to provide short duration illumination to the scene 104 at the same time, corresponding to the odd frames in the sequence of frames 120 (shown in FIG. 1A).

[0070] The second lighting setup 504 includes the light source 408, being synchronized by the controller 102 to provide short duration illumination at times corresponding to the even frames in the sequence of frames 120 (shown in FIG. 1A).

[0071] With reference to FIG. 6, a schematic diagram of a top view of a scene lit with four light sources is shown of an apparatus for recording a scene using multiple lighting setups 400. Included is the controller 102 in communication with the camera 106 configured to record the scene 104. In this embodiment, the light source 404 is included in a first lighting setup 602 to provide light for the scene 104. In addition, the light source 402, the light source 406, and the light source 408 are included in a second lighting setup 604 to provide light for the scene 104.

[0072] The controller 102 activates the first lighting setup 602 at a time within the odd-numbered frames of the sequence of frames 120 (shown in FIG. 1A), and the controller 102 activates the second lighting setup 604 within the even-numbered frames of the sequence of frames 120 (shown in FIG. 1A).

[0073] The first lighting setup 602 includes the light source 404, being synchronized by the controller 102 to provide short duration illumination at times corresponding to the add frames in the sequence of frames 120 (shown in FIG. 1A).

[0074] The second lighting setup 604 includes the light source 402, the light source 406, and the light source 408, all synchronized by the controller 102 to provide short duration illumination to the scene 104 at the same time, corresponding to the even frames in the sequence of frames 120 (shown in FIG. 1A).

[0075] With reference to FIG. 7, a flow chart is shown for a method 700 for recording a scene using two alternating lighting setups so as to concurrently produce motion picture footage of the scene for each lighting setup of the scene, the motion picture clips having minimized time offset with respect to each other. The method includes selecting a plurality of light sources 702, with each light source configured to illuminate the scene 104 (shown in FIG. 1A). Subsequently, the method 700 includes selecting a first lighting setup 704 from the plurality of light sources, selecting a second lighting setup 706 from the plurality of light sources, the second lighting setup selected being different from the first lighting setup. Subsequently, the method 700 includes actuating the first lighting setup and the second lighting setup in alternation 708, in accordance with a timing signal, including actuating the first lighting setup just prior to an end of a frame, and actuating the second lighting setup just after a beginning of an immediately subsequent frame. The method 700 also includes capturing a sequence of frames 710 using a camera, each one of the frames showing the scene illuminated by one of the two lighting setups in alternation. Optionally, the method 700 may include processing the sequence of frames 712, so as to generate two separate clips of footage of the scene, each clip corresponding to one of the lighting setups.

[0076] 1/60th of a second is a common threshold whereby a number of everyday types of motions appear frozen at this speed or faster. Accordingly, a simple formula has been developed according to the invention to find the outside limits for when the first lighting setup begins to fire and the second lighting setup finishes firing.

[0077] The formula is: d=b/2, where d=the time from when the first lighting setup starts firing until the end of the frame it is in, and also d=the time from the start of the frame the second lighting setup fires in until the end of duration of the second lighting setup. Therefore, b=2d, i.e., the base frame rate is DOUBLE the finishing frame rate

[0078] For example, 30 frames per second is the desired finishing frame rate, so the base frame rate is 60 frames per second, which equates to 16.67 milliseconds per frame. Half of this is 8.33 milliseconds. Thus, from the start of the first lighting setup firing until the end of the frame can be up to 8.33 milliseconds. Also, the beginning of the next frame until the end of the second lighting setup finishing firing can be up to 8.33 milliseconds.

[0079] The total time from the start of the first lighting setup firing until the end of the second lighting setup firing therefore is 16.67 milliseconds, which is just above 1/60th of a second. Therefore, the formula indicates a limit at 30 frames per second, so that for lower frame rates, the maximum time is still 16.67 milliseconds.

[0080] Other modifications and implementations will occur to those skilled in the art without departing from the spirit and the scope of the invention as claimed. Accordingly, the above description is not intended to limit the invention, except as indicated in the following claims.