No, you don't multiple expose the same frame. You take multiple frames(many exposures) then use specific software designed for the purpose to "stack" the images to net one better image. There are several folks who specialize in this software, from relatively cheap to relative expensive. They are all designed around using with telescopes and either dslr cameras or ccd cameras specific to astrophotography. It turns out that the Canon cameras are very well suited for this purpose, followed by the Nikon D50. The new D200 is also very promising. My isdDL is pretty noisy at exposure times longer than 3 minutes and iso's above 800.
-- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
