Ive seen some reviews stating the 6D has very bad moire in video and pattern shots. Perhaps a very limited AA filter? wonder if anyone has tested this yet? 6D perhaps a good landscape/studio cam?
The AA filter is very different to the software process that goes on to scale down the frame into the video resolution. The AA (or low pass) filter blurs the image to approximately the correct amount to make the four R G G B bayer pixels blend into one - thereby almost completely eliminating false colour from the image that could be caused by high contrast fine detail just exciting the one colour pixel. This AA filter is required for both stills and video as the false colour cannot be removed in post processing, even when downsampled.
The video scaling is needed for rendering a low res image from the high res frame. If its done the simple way as on the 6D (and most other SLR's), instead of using the best part of 9 pixels combined to produce the one in the video, it just uses one. That way, the video has a tendancy to look very sharp, but moire (not colour moire) occurs with high contrast fine detail. For instance, fine parallel lines such as a wire fence could mostly miss the pixels which are used, and the ones which are would intermittently see the fence to produce a fairly ugly looking pattern. Again, this moire is impossible to remove in post processing. The 5D mk III uses exactly 9 sensor pixels downsampled into one video pixel to avoid this moire.
Wow. $500 + shipping to remove the AA filter. What level of improvement could be expected after that investment? And how would it affect the resale value I wonder?
It would get the image nearer to the full native resolution of the sensor, but at the expense of colour moire. Unfortunately, the only time you really want that extra resolution is when shooting fine detail with a very sharp lens, and that's the exact time when colour moire will show up. The best way to avoid it is to use a small aperture to blur the image enough to avoid moire, or tweak the focus ring a bit to deliberately mis-focus the shot. Either way, you're not getting the full resolution. Either that or don't under any circumstances photograph any high contrast fine detail with it.
The D800E gets away with it to some extent because its pixel density is so high that the average lens, its AF system and using it on less than a perfect tripod all add up to produce enough blurring to reduce moire.
Try an original Canon 1D if you want to see moire - such a low res sensor with no AA filter doesn't look pretty with fine repeating patterns.
