History. Bought a 8" "50" inch fl parabolic mirror for a new wide field project. Tested the focus point, came out to 40" per John Dobson vid and other members. Plugged my numbers into Newt for the web, cut tube, made frame, 2" focuser, 52mm diagonal cut holes finished tube sweet mounted and preliminary did the collimation. Tested outside at power tower 3 miles away. couldn't focus a thing.
Re tested Image of flashlight in yard focused on sheet of paper at dead nuts 40" O.K. f5, Plugged in again to Newt for web, re cut, no dice.
New tube remounted everything STILL nothing.
When I look at the secondary with the focuser removed, there is a perfectly clear image of stuff at least 1/2 mile away.
I am out of Aleve and need some expertise..