I've been assuming that all other things are equal on the two types of systems. The 1DS is 76 square microns per pixel and by my calculations the Leaf Aptus 17 is about 91 square microns/pixel. Smaller pixels should result in less moire for all other variables being held equal yet you are saying you see more moire with the smaller pixels.
Obviously this make my assumptions questionable. I just yesterday saw a shot of a building in NZ or SA I think with a lattice exterior that showed moire on a 1DS3 and then showed a capture 1 tool that removed the colors but the banding was still there.
Maybe there is something the MF back do other than aa filters that remove the moire or maybe the aa filter itself causes moire that might otherwise not be there?
I've never seen moire on my sigma and the leica shooters report not seeing it either. The sigma is different of course in not having a Bayer filter but the leicas and all the MF backs do and they still don't have moire problems. The sigma does show aliasing when the target objects get below 1 pixel but the aliasing even though it is false data often fits well into the image and doesn't look bad at all.
Mike
For a scientific standpoint I'm sure all this talk of microns and pixel size makes a difference, but moire is just something that happens to all cameras if you walk into the perfect storm.
Color moire can be fixed fairly easily, pattern moire is a nightmare.
Now whether a mfdb moires more than a dslr is more dependent on what you shoot, how you shoot, the lighting you use rather than any scientific standards.
I have a friend that swears he sees pattern moire on jeans, though I have shot a billion pair of jeans in all shapes, sizes with cameras ranging from all the Canons, Leaf Aptus, Phase and rarely if ever (I think ever) have seen pattern moire on jeans.
It's easy to think that a digital back sans aa filter has a tendency to moire more than a dslr, but usually a digital back is used in a locked down position with tripod, and/or with a large quantity of light, usually strobe, which just adds shaprness and more chances of the perfect storm. With dslrs, they are usually hand held and more or less shot with continuous or available light so though moire can happen, there is a lot less chance of it happening in every frame.
The only way to be sure that you don't have moire is to tether the camera on a large screen with clear previews and this holds true with any digital camera.
Given this, I find moire to be less of a problem than ever, as cameras have improved. Also going to continuous light seems to limit it, though probably limits pin point sharpness also.
The only time I saw moire that was almost impossible to control was when I shot with a 22mpx back, though the project that had moire was men's suits with pronounced patterns and probably any camera in those conditions would be difficult to control moire.