Help with Moire Problems

J

jsauce

Active member
just took the 7d on an intensive shoot in costa rica for a client. mostly good results but i had some severe moire problems on a bunch of shots. i have 2 questions here.

1) what can I do in post to try and fix this?
deinterlace? unsharp mask? or do i need post house garbage matting solutions?

2) how do we avoid it in the future?
it seems like moire is only appearing when I shoot at 60 frames a second (overcrank) and when im shooting big wide shots with a deep aperture. it really seems about trying to get too much information in focus.

thoughts?
 
jsauce said:
2) how do we avoid it in the future?
it seems like moire is only appearing when I shoot at 60 frames a second (overcrank) and when im shooting big wide shots with a deep aperture. it really seems about trying to get too much information in focus.
Click to expand...
Read the Aliasing article to understand what's happening.

Yes it'll be more likely to happen on 720p mode, because the 720p mode is much more prone to heavy aliasing. And, yes it'll happen more often with deep-focus shots. Basically it can happen on anything that's in crisp focus -- so a wide shot, with more in focus, makes it more likely to happen.

Your methods to avoid it are limited to basically two techniques:
1) use a different camera that doesn't alias, or
2) don't use super-sharp focus. Using a Caprock anti-moire filter or a soft/fx filter or actually defocusing slightly can make it go away.

As for fixing in post -- you can use a chroma blur to minimize some of the rainbow effect, but you cannot get rid of the actual luma aliasing, that's "baked into" the footage.
 
anybody had any luck with other fcp filters by chance? trying to salvage some badly damaged shots
 
Martin Koch's filter for FCP doesn't work on H.264. Has to be converted to ProRes or other first. Then should work pretty well. The rainbow will be gone, however the marching ants will still be there.

For the 7D, it seems the Caprock 2.0 is the right value. For the 5D, the jury is out. The 2.0 doesnt cut it. I am waiting for a 1.0 to do some testing.

Also I have found that if you make a picture style profile which is based upon neutralizing your grays and then turn down sharpening, contrast and saturation in camera, you get rid of much of the color aspect to moire. It does not reappear when those values get pumped back up in post.
 
Barry_Green said:
Read the Aliasing article to understand what's happening.



2) don't use super-sharp focus. Using a Caprock anti-moire filter or a soft/fx filter or actually defocusing slightly can make it go away.




Barry, I've asked about the effect using Tiffen SoftFX filters many times, but this is the first post anyone else has mentioned them. I have a .5 / 1.0 and 2.0. What is your experience with them?
Click to expand...
 
ROCKMORE said:
Barry, I've asked about the effect using Tiffen SoftFX filters many times, but this is the first post anyone else has mentioned them. I have a .5 / 1.0 and 2.0. What is your experience with them?
Click to expand...
With a DSLR? None yet. But anything that takes the sharp edge off has to help...
 
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