Originally posted by vonBaloney Another trick if you've got stacking software like PhotoAcute (which can also increase resolution) for stationary subjects is to take several shots of the same thing and stack them -- it puts them all together and removes the noise by keeping what's common between the images. The newer Photoshops also have stacking, but I haven't tried it -- don't know if it will remove noise or if it is just for focus stacking. PhotoAcute is really cool though.
Is this included with the non-Extended version of CS6 now?
This used to be an option in the Extended version only. (perhaps not stacking, but at least the blending of stacked images). I have not seen a bullet point if this is supported in non-Extended now.
Also useful for removing pedestrians from slightly crowded tourist sites and slightly useful for merging for star trails, etc...
As for upper limit on auto ISO?
I set my upper limit to 12,800. Better to have some grain than blur.
You just really need to shoot some photos and get used to how your camera behaves. Then choose what is acceptable to your own taste and needs.