I'm going camping next weekend in Joshua Tree, and I figure this might be a good time to try a few shots with star trails. Looking at a lunar callendar, it looks like the moon will be roughly 1/3 lit.
I've never attempted any exposures longer than about 30 seconds. I'm guessing that with reciprocity, if I just leave the shutter open for a few hours at f8, I'll get something of what I want. Will this make the ground to bright though, with about 1/3 moon?
Film I'll be bringing is Tri-x 320, and Provia 100f, shooting 4x5 with both of them, and 8x10 with Tri-x.
Any suggestions for aperture and shutter length for each of these films? I'll have more than one camera with me, and I'll be there for more than one night, so I don't mind leaving one camera in use for some long shutter speeds, 3 hours or so. I won't be staying up all night, so I don't think I'll be able to do a 6 or 8 hour shutter.