Originally posted by LesDMess - This was shot at f2.8 with ISO 50 Velvia. I figure to try f5.6 next.
Yep, maybe a wee bit light...
What I did when I took my first one, was to start at the widest aperture & leave that for 10 or 15 min., then stop down one, leave that 15 min., then stop down again, & so on, up to f22. That way you get a test shot which shows you which aperture was best. Use a bright star or planet for reference, & you can then decide which of the lines you best like the effect of. I think I put the lens cap on for a few min. in between apertures, just to differentiate them. You get a dotted line of various thicknesses. Haven't got a scan of it handy but hope that makes sense.