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In-Focus problems: options with Pentax *istD on 5" Newtonian
Got a Pentax *istD that I want to use on prime focus on a small 5" newtonian (FL=650mm). I measured the distance between primary and focus point after reflection on the secondary. With focuser completely in the tube I have 30mm to play with. By the time I stick an adapter + T-Ring + camera I don't think I can do that within my 30mm budget.
I'm new to this kind of set-up because I currently use a Nikon Coolpix 995, that allows me to zoon in and out with a William Optics 28mm lens adapter. That was very flexible to focus and zoom in/out.
Now with the pentax bare case there's no more lenses involved right?
What are my options to get as close as I can to the flexibility I had wit the Nikon? Is there some kind of set-up including extra intermediate lenses that would help me to achieve this? Thanks for your help.
PS: moving primary closer and re-drilling the tube is not an option. I don't think I can move it in that much. Maybe get a shorter focuser?
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