I finally found a few minutes to test out the ISO range on my 60D. I got basically what I expected, but one thing that suprised me was the dramatic drop in saturation at high ISO. The camera can reach ISO 6400 natively and then expand to 12,800. It's probably safest to consder these only usable in emergency situations... The noise is very high. Maybe if you're going for a "look", you won't mind it, but I find that doubtful. Anyway, check out my results!
I shot all of these on my new 40mm f/2.8 pancake lens AT f/2.8. This can sort of double as a sharpness test, but I'll probably do more on that later. This is at ISO 100. Nice and bright. The wood grain in the guitar really shines here.
I decided to jump right to ISO 800 to keep this test on the shorter side. No sense in going all the way through every setting. The guitar is a little less bright but still plenty usable.
ISO 1600. The maximum range of my prevous DSLR. Things are starting to get a little noisy here, but I'd still use this image. I don't think the noise is unreasonable. I'd probably want to boost the saturation in Photoshop, however.
ISO 6400. Yuck. Faded, pale, noisy.
Lastly and definitely least, ISO 12,800. This is the expanded ISO range. No thank you. Double yuck.
And just in case you needed ANY convincing...