I haven't done a lot of night-sky photography. Long ago in Montana, I used to shoot lightning storms with some success, but I haven't done any long-exposure shooting in quite awhile. I'm going to try to get some photos of the Perseid Meteor Shower tonight, so I've been reading up on how to get the best shots.
There seem to be two different camps in the long-exposure star photography world. One says to crank up the ISO to get the fastest shutter speed possible, and the other suggests using a more modest ISO to cut down on the noise. Both sides make good points. A faster shutter speed eliminates unintentional star trails, but the high ISO makes for a noisy image. The lower ISO might cut down on noise, but requires a longer exposure--so there's more of a chance those star trails detracting from the meteor trails.
So, I intend to try both tonight. Actually, that has always been my favorite way of learning anything related to photography. Do a little research, then experiment extensively to see what works best for me.
Below is a great article on PopPhoto with tips on how to go about shooting a meteor shower.
Are you going to be out shooting tonight (or did you go last night?) What technique worked best for you?
UPDATE: Just found out that OMSI is doing a Star Party Sunday night. For those of you in the Portland area, it might be cool to go with a group that knows a thing or two about astronomy. :)