Quick question please and thanks new for your help

[dijames]

I'm wondering how you decide what distance you put between your telescope, flattner and camera? Is there a formula?

[Nikolas]

What sort of camera? What brand of flattener? What sort of scope?
On my rig it's 55mm from back of flattener to the sensor of the camera, too many variables

[dijames]

ZWO ASI 533 MS PRO camera, SharpStar Flattner and a Sharpstar AL-90II apo Triplet F6.7.

[Nikolas]

If it's the 2.5 inch flattener then this will help


Refractors with a focal length up to 500 mm 106 mm distance
Refractors with a focal length between 501 mm and 600 mm
101 mm distance
Refractors with a focal length between 601 mm and 700 mm
96 mm distance
Refractors with a focal length between 701 mm and 800 mm
91 mm distance

Refractors with a focal length between 801 mm and 950 mm
88 mm distance
Refractors with a focal length above 1000 mm
87 mm distance