Moiré Effect With Nikon Z7 ii and Nikon 50/1.8 S

[gskibum]

I've set up a copy stand to capture a whole lot of content of various media and various sources. My first project is an old album with some grayscale halftone-printed photos scattered here and there. I wouldn't be surprised if some of these are second generation images.

For some reason I am getting a Moiré effect when capturing halftone-printed originals with a Nikon 50/1.8 S and a Z7 ii. But no Moiré with the Nikon 24-70/2.8 S lens. This particular image has a line screen so fine, I had to put a loupe to it to see it. I wonder if I would have still needed that loupe 30 years ago. :-)

I'm going to go ahead and do this project with the Nikon 24-70/2.8 S, no big deal. The small difference in image quality between lenses just don't matter for this project. My post isn't so much asking how to fix this, but I'm really surprised to run into a Moiré effect at all. Where is it coming from?

With the 50/1.8 S I had the camera set as high up as the copy stand will allow so I could capture as much image area as it would allow. That is when I saw the Moiré. If I move the camera 3/4 of the way down the shaft the Moiré effect goes away.

I hope the 35mm f/1.8 S I'm going to buy doesn't have this issue. I need the 35 to capture the 20" x 20" image area of my copy stand.

I can upload portions of images if anyone wants.

[degrub]

Just curious, did you try rotating the camera around the longitudinal axis of the lens to 30 deg and 45 deg ?
Also,  stopping down to F8 or higher ?
Does a sheet of museum glass on top of the image help ?

Or try a different sensor body ?

Usually, i would want a flat field lens for copy stand work - a macro / micro lens. Is the 35 adequate ?

[kers]

The 50mm is sharper and it results in moiré from the sensor bayer-grid in relation the halftone grid.

The way not to get moire is go closer or further away and/or use f11 or f16 to make the lens less sharp.

- another way is to use pixel shift - with 4 images combined you have no bayer pattern and that also reduces moiré, and better color;  but the z7 II does not have that option.

I just ran in that same problem myself today doing repro work and used the latter method with the z8.