Iso

[jenvdw2]

hi does anyone think that if shooting a dark subject low light conditions indoors at long slow shutter speeds could compound the noise at high ISO?

[ttclett]

Most noise is seen in the blacks
Most high ISO shots have sensor noise
Dark subjects have blacks
Low light conditions require slow shutters and / or high ISOs
Slow shutters increase the chance of soft focus or motion blur

Your question suggests the answer to all aspects is yes!