Thanks for posting this! I learned a lot by listening to the whole seminar.
Of course, I immediately compared my puny effort to theirs and was intrigued by the formulas for calculating the apeture and effective fl of multi telescope systems:
A = V n x size
fl = individual fl/ V n
n = number of lenses
V = square root (how do you get this sybol on an iPad?)
I'm wondering if anyone knows the formula for A (aperture) for combining lenses of different size (in my case 140 and 180 mm)?
I took the average of using 2 140 mm + 2 180 mm lenses and got 225mm. Not sure if that would be correct. Since both scopes are f7 I think my system is equivalent to f4.95.
Thanks,
Peter
