Originally posted by rawr I also like Auto ISO. With the K-x there is little reason to be worried about high ISO.
Most of the time in daylight - even when birding - I have it set at Auto - 3200 and on Av, and the camera chooses ISO and shutter speed pretty sensibly depending on my lens etc. If I'm out shooting live music in a pub or club I let it go to Auto - 5000. If I'm walking about in a dim museum or at night, I let it go to Auto - 12800.
PP can clean up any noise, if it gets noticeable.
1) PP = time. Get it right the first time.
2) I set my ISO to Auto with a 1 stop difference. Any more than that and I start to lose contrast and resolution beyond my intent. Outdoors I set it between 200-400 (K-x) because that is where the sensor peaks. Indoors 400-800, with bounce flash or natural light, depending. In
extremis, ISO 1600 because by then there is a noticeable loss of colour fidelity. At 3200 not only is there visible noise (NOT "grain"), but distinct loss of DR.
I think there is a solid case for Auto ISO, but as with most things, there are limitations to its practical functionality. There's nothing worse than having the camera bump the ISO to something ridiculous for a well-lit outdoor scene because there is some low contrast area, when what is really required is EV alteration. This is where Auto ISO really messes up. If not prescribed properly in Auto mode, it simply becomes the wrong tool for a correct exposure.