Many photographers that are shooting for the micros often are concerned with relation to situations where there is low light and a high ISO is required. I've heard artists ask if they should just skip the image altogether and are frustrated with relation to low light situations. Here are the options that I've used to help me get around the situation:

1) Use a tripod and a lower shutter speed at 100 ISO.

2) Shoot at a high ISO and bracket up (over-expose) by about 2 stops, then bring the exposure down when processing the image. You will get less noise this way.

3) Shoot at high ISO, then process in Neat Image. You'll be surprised sometimes what you can save. If that doesn't work, reduce the size of the image to hide the noise (a big option at the micros).

4) Process for noise using ...