Noise

Just a simple question, most probably difficult to answer....
High ISO setting produces noise.
Long exposures cause noise too.

What is worse?

I've got an upcoming shoot in pretty dark circumstances. Luckily for the model there is an opportunity to lean against a tree, so I can use pretty long exposures. But what is the best way to choose in this digital era?

Leen

I haven't compared the two options side-by-side, but I am very impressed with the ability of the recent digital cameras to handle high ISO settings without excessive noise, and then the longer shutters speeds is less of a problem.

Travis

I would say go with the lower ISO and longer shutter speed.

Below is a picture I shot with a Canon 10d, which while good is supposed to be noisier than Canon's recent offerings.  It was a 30sec exposure at 100 ISO.  There's really not a lot of noise.  When I usually get noise on this type of shot is when the RAW converter tries to lighten it up by using the exposure level. 

Edit: Should've looked at that one after saving but before posting.  There's some pretty bad JPEG artifacts in there.  It looks better on the original.