WARNING: Nerdy tech content. If you’re shooting a lot of video with all the video dSLRs and even the iPhone 3Gs, you’ve no doubt noticed the slight “wobble” when panning those cameras quickly. It usually translates visually into the slanting, or canting, of what are supposed to be vertical lines in image that you’re recording. This phenomenon is the result of the digital rolling shutter, the mechanism by which these cameras write to their chips. As it writes information to the sensor, it does so by writing from one side of the sensor to the other. And if the subject in view is moving faster than the camera can draw that image on the sensor, the camera perceives a bending or warping of that subject. As photogs/filmmakers rapidly adopt these new cameras there’s an increasing need to create elegant solutions around solving this problem. In comes the fine folks at the The Foundry in the UK.
“Rolling shutter effects are commonly found with video cameras employing CMOS image sensors, which record every frame line-by-line from top to bottom of the image, rather than as a single snapshot of a point in time. As parts of the image are recorded at different times, fast-moving objects, or objects that pass quickly through frame during camera whip-pans, become distorted with diagonal skews. Other typical distortions include image wobbles created when cameras are hand-held, and exposure problems with flashing or strobing lights….
Along with being ungainly and unwanted, these image distortions also increase the difficulty of 3D tracking during VFX post production, as the tracking points themselves can be equally affected or not deliver accurate results.”