>On the terminology, I think I meant a "dark" as >opposed to a "dark flat", which is indeed as you >describe. >
OK, just wanted to be sure. There is a flat field correction, but that is generally not used for astrophotography I would think.
>FYI, I've put two images here, one a dark taken as a RAW/NEF >(whihc looks terrible) and one taken as a jpg, which looks the >way I think it should look: >
I downloaded the NEF and opened it in Photoshop CS3 and it appeared black as I expected it to be. I then adjusted levels to bring out any possible sensel variation and a few pixels appeared, but nowhere near what you described. So it appears that it is possibly PSP X2 that is giving you a false rendering.