I am trying to get into deep sky astrophotography, but have ran into a number of issues. I tried using an uncooled planetary camera, but even with three minute exposures, I could only see a handful of bright stars and I couldn't see my target at all. I hoped that processing would reveal more, but even deep sky stacker couldn't detect enough stars. I have a dslr that I'd like to use instead, but it will not reach focus. My telescope is an F5 Newtonian, and the focuser doesn't seem to have enough travel to allow the dslr to reach focus, unless I use a barlow. Is there a way I can fix this without replacing the focuser?