[raymo]

I have always noted that some imagers take subs of 3,5,10 minutes, or even
longer. How do they do that? The max I can go before blowing out pretty
much everything is about 100- 120 secs. I have a pretty good sky at Bortle 2 to 3. I had the same limitation when using my 8" f/5 Newt as I now do using just a DSLR and a lens.
raymo