Is this the best you can expect from 1600 iso

[arith]

Now I have an f1.8 and can go up to 3200 iso I could get 1/30 and in exposure; but I'm not going to bother.

[Colin Southern]

May I know why I should stack multiple exposures when I can just shoot 1 low-iso shot? If I'm not mistaken, the multiple exposures need to be alligned rather well which means a tripod is required. A low-iso shot in the dark also requires a tripod. To my thinking, the latter requires less work while giving similar results.

It depends on the length of the exposure - even low-ISO shots will eventually accumulate noise (and without a remote release, it might not even be possible to get a shot longer than 30 seconds). As a rule of thumb, divide the ISO by 100, and that's - roughly - the number of shots you need to take at high ISO (that are then subsequently averaged) to give you close to an equivalent "base" ISO shot, in terms of noise.

Note: All of this is assuming done on a tripod.

PS: I know this is a very old thread - just thought it may help anyone searching the site, or even spur some current discussion on the topic.