Between a Nikon D70S (6.1mp) and D200 (10.2 mp), does a higher resolution mean less noise at higher ISO?

Answer 1

Usually, given the same size of the imaging sensor (CCD), the higher solution (mega-pixels) would have more noise. But since the D200 is a newer camera, and that it's a higher model, Nikon has probably tuned the firmware to reduce noise at higher ISOs.

Here's a side-by-side comparison with user reviews/ratings:
http://www.dpreview.com/reviews/compare_post.asp?method=sidebyside&cameras=nikon_d70s%2Cnikon_d200&show=all

Answer 2

Yep, yep, the D70s and the D200 use sensors with the same physical dimensions. The D200 crams 4 million more photosites into that space by reducing the size of the individual photosites, which reduces their light-sensitivity... which would normally increase noise. But the D200's newer generation sensor is also better at compensating for this. The net result is that the D200 produces cleaner images.
Actually, in the Nikon lineup, the humble D50 is your best choice for high ISO shots.
And if shooting with stratospheric ISO values is *really* important to you, get a Canon 5D.

Answer 3

It's mostly irrelevant. The quality of the sensor is what determines noise levels at higher ISO. Taking the same size and quality of sensor and jamming more megapixels on it will increase noise. However, most dSLR cameras have high quality sensors and keep improving them. If anything the D200 has less noise thant the D70. More megapixels but a better sensor.

Answer 4

I own both cameras and the D200 has less noise at comparable high ISO's. I have not really done a scientific study on this, but I think the noise reduction on the D200 is a little better, also. Panacea's explanation makes sense to me.

http://www.dpreview.com/reviews/compare_post.asp?method=sidebyside&cameras=nikon_d200%2Cnikon_d70s&show=all