- #1
mishima
- 561
- 34
Hi, I recently made a little cover for my telescope. It was just a piece of wood with a 15/16 inch (24 mm) hole in it. I was wondering how to calculate the new f-ratio.
Original focal length: 1370 mm
Original primary aperture 150 mm
Is it as simple as 1370/24=57? Just treat the hole like the new primary?
Original focal length: 1370 mm
Original primary aperture 150 mm
Is it as simple as 1370/24=57? Just treat the hole like the new primary?