Hi all,
Wondering if anyone can help with correctly calculating my systems actual F ratio? I'm ultimately interested in working out my critical focus zone per filter.
I've seen the below calculation, but I'm unsure how to work out the affect of the AOL and filters on this F ratio number:
CFZ (in microns) = 2.2 x (Ft)2
where Ft is the
true focal ratio (focal length / aperture) of the optical system (i.e. including the affects of focal reducers, barlows, filters, etc.)
http://astro.azurewebsites.net/Artic...icleContent/11
My system is F8, I use the AOL and Astronomik CCD filters. CCDAP suggests the following:
CFZ [Red filter]: 66.6micron
CFZ [Green filter]: 56.3micron
CFZ [Blue filter]: 46.1micron
How does that work?
Thanks!
Steve