Lowering Resolution on Camera - Effect on noise?

[itznfb]

top: jpg L ISO100, jpg M ISO100, raw ISO100
bottom: jpg L ISO1600, jpg M ISO1600, raw ISO1600
all 100% crops.

to me the best quality definitely jpg M. jpg L doesn't look as good as jpg M but it still looks better than the RAW shots. reason being, the in-camera sharpening and color correction is better than photoshop or whatever you're doing your editing with. and with M, it's just resizing L, so it's obvious why that is more sharp.

 

[astrostu]

So with these examples, one thing that I just thought of that hasn't been mentioned is the JPG compression. Again, this is a case of I don't know exactly what the camera does, but one thing to keep in mind is that JPG is a lossy compression algorithm, and you can set the quality level (lossy-ness). It is possible that the camera will save the smaller JPG files at a more lossy level than the largest, which then becomes another variable in the equation.

What this all boils down to for me is what I've done all along: I shoot in RAW and do all processing and re-sizing myself. That way, I know exactly what's going on in any resizing that's done.