> >Also, that subjective evaluation can vary depending on subject >matter. > >Bird feather detail for example does not hold up well to >noise. From my limited experience - I think sports shooters >run into noise issues at lower values than many others do the >poor quality of light in the venues. >
LOL. So apropos. The other day I took some shots of a peregrine falcon with my D7000 at ISO 1250, nesting on a concrete bridge piling. Every photo is a reject; way too much noise after cropping. Crank up the noise reduction, and all feather detail disappears.
(Now, maybe if I had 1000mm/5.6 glass, it would have worked...but I didn't. Couldn't get any closer, either. My 320lb butt rapelling off the side off an 8-lane turnpike bridge to "get the shot" is not going to happen.)
For other subjects, ISO 1250 is just fine, and the noise is easily handled in post processing. I've shot entire indoor events at ISO 3200 and gotten acceptable results printing to 8x10.