[Steve14 (Steven)]

I was hoping for some advice on getting a daystar quark so i can attach it to my 102mm F5 apo refractor for solar imaging. I'm worried that i may not achieve focus as it has an inbuilt 4.3x barlow. The back focus of the scope is 80.3mm.
Daystar recommend either not using a diagonal or using a focal reducer if there are issues. However, i'm unsure if this will resolve any potential problems and i don't want to buy the quark only to find out i cant use it. Is there a way to figure it if it will come into focus based on the telescope and filter specs?


PS i'm aware that i have to use an UV/IT cut filter for telescope apertures larger than 80mm...
Thanks for any assistance.