Hi Mohammad,
I think I need to point towards Octans, being in the southern hemisphere
Can I ask you why a 5D wouldn't be any good? I have the MK I and I can turn off long exp NR which is responsible for the black frame.
I think my computer could handle it - it's the latest 2 x 2.93 tower chock full of RAM
Woody - You may be fine with the Hassy - each back has it's own method of determining when to do a black frame afaik. I think the Sinar calculates how long it has been since the last exposure and if it has been longer than say 5 or 10 minutes it decides it should take a black ref frame after the next exposure. So I don't know how it would go if I just did continuous 1 sec exposures back to back. It may pause after 10 minutes to do a new black ref file then keep going. On the eMotion backs you can force it to take a black ref after the next image is captured by pressing a button in the menu - I don't know what this is for. However I have discovered it will take a black reference image after every capture if the shutter speed is longer than 1 sec.
Maybe I'll get some sort of image wide open at 1 sec if the stars are bright and I could bump the ISO to 200. The NR in the Sinar software is very good, so might be able to clean up the noise without killing the stars. Also could play with the black clipping as Doug suggests although I haven't read his thesis.
Ben
Ben