A friend rendered a very cloudy, sun almost set night scene.  It's quite beautiful but when you zoom in on it, it has a pixely look to the clouds.  Is this because it's a night scene?

Is there a setting to offset this issue?

Is the non-zoomed render pixely?

He was probably using Spectral 1 clouds, or old MetaClouds. Using Spectral 2 clouds doesn't create such artifacts, but it can also be down to the cloud model he used, some have nicer density production than others. It's hard to tell without sdeeing the render.

I'm going to try and attach a screen shot from my Poser with the background loaded on a a grid.  I can see some striping in the sky areas and it seems blotchy to me in the clouds.

Forgot to say that that is defaut Poser 9 lighting.

Oh, you mean you used this rendered sky as a backdrop in Poser?  Well, in this case, it  may well comes from too  low res  a render? Which format is it? I would suggest 16bit tiff, tiff is uncompressed to avoid pixellation, and 16bit to avoid banding.

I think I know what the problem is.  They sent me PNGs on all the other images but this particular image is a jpg.  I think it was saved incorrectly.  I'll ask for it resaved and hopefully this will solve the issue.