“Aliasing” and “Moire”
The new “HDSLRs” do a fine job of shooting very nice HD video. But almost all are plagued by several problems that can ruin a good shot.
These problems are “rolling shutter” (previously written about on this blog), and “aliasing” and “moire”. Aliasing tends to introduce fake detail into an image, fooling people in to thinking its a sharper image than it really is – because its fake. Moire produces bizarre color patterns wherever there are narrowly spaced, using horizontal lines in the image.
This Barry Green article is the best explanation I’ve seen for explaining and illustrating the aliasing and moire problems with DSLRs shooting video: DVXuser.com – Articles.
A great visual example of a moire pattern showing up in a real life situation is this video clip – about 30 seconds long. Just look at the roof of the hotel and watch all the false color shimmering going on. This example was shot on a Canon DSLR.
Here’s another example – look at the sofa cushions: