[Mark Fraser] “Any advice?”
Get a different camera! 🙂
But seriously, the problem is with the camera, not your lens, ISO, shutter speed, etc. Moiré in Canon DSLR’s is a long documented fact stretching back to the 5D Mark II. Much of the problem has to do with how Canon is taking a 20MP sensor and getting down to a 2MP image (spoiler alert: line skipping). Couple the line skipping with a subpar codec, h.264, at modest bit rates and you have a perfect storm of moiré brewing.
So honestly, your lens or camera settings aren’t going to help because the problem is largely happening internally between the sensor and the compression. Your best solutions are to avoid shooting tight patterns, use a different camera when those scenes arise, or learn to embrace it. :-/ Your last set of options boils down to “fixing it in post” and there are plugins that can help manage it, but will not entirely eliminate it. Neat Video and Digital Anarchy make plugins compatible with most modern NLE’s that can help you blur/soften parts of the image which help reduce moire (or noise).
Ryan Holmes
http://www.ryanholmes.me
@CutColorPost