December 21, 2010
Rolling shutter artefacts: fix it in post
Anyone who pans a DSLR while shooting video will notice that any vertical lines in shot lean over. On some DSLRs you can barely move the camera without this happening. It is a fault inherent in the way CMOS sensors are read out. It can be addressed if the manufacturer uses higher clock rates, but is difficult to avoid completely.
It is, thankfully, something that can be fixed in post (although rarely perfectly), with a variety of software plug-ins. These range from high-end products, such as The Foundry's RollingShutter (costing £300 for After Effects or its own Nuke compositor); or more affordable varieties, such as CoreMelt’s Lock & Load X ($149 for Final Cut Pro and After Effects), and its latest $79 version, Lock & Load Express, which is the first stabiliser for Final Cut Express.
This sort of software can be surprisingly effective, even the stabilisation option in Apple's latest version of iMovie can restore demented verticals (as Philip Bloom demonstrates on his blog).
Lock & Load Express can give hand held footage "a professionally shot steady cam quality instantly without the need to set tracking points," claimed CoreMelt founder, Roger Bolton. It is not as sophisticated as the version for Final Cut Pro, which is claimed to be "one of the fastest video stabilizers available" at least 12 times the speed of FCP's built-in stabiliser (whereas the express version is just six times as fast as FCP), and offers more advanced tracking features (including keyframes and background processing). Lock & Load Express has presets for the main HD DSLRs, CMOS camcorders such as Sony's EX1, and the likes of Apple's iPhone or the Flip HD.
By David Fox