“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:

canon eos 60d video “moir√©” problem at 1280×720 50 from emre karabakan on Vimeo.

3 thoughts on ““Aliasing” and “Moire””

  1. Thank you for the article. I have been trying to get rid of this problem for a ling time. Now I know what is causing it. But I would like to know if the new Panasonic Af100 would have the same aliasing and moir problems solved. It has a large cmos 33.3 mm and it is good with shallow d.o.f.
    Cheers Amir Ghahrai

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