Quote:Tim if you want a wide field reflector I can't imagine you will be satisfied with anything less then something that you have created in your own special way.
Here is an article that gives food for thought;
Rich field by Mel Bartels
Mels 13 inch f3;
Celestron 8SE Dobstuff 13.1": Swayze refigured Coulter mirror, 6 pt mirror cell (2 pt edge support) and CF focuser board made by me StarBlast 4.5 ST80/PortaMount II Zhumell 20x80/Oberwerk 15x70 on a Seronik-style tripod boom mount Hubble Optics 18 inch F/4 mirror.
Quote:There are two reasons though to tweak his numbers - the generous pupil size he used (7mm) and the advent of the ES100 25mm eyepiece.
Quote: Quote:There are two reasons though to tweak his numbers - the generous pupil size he used (7mm) and the advent of the ES100 25mm eyepiece. Carey:I think if you look at Mel's analysis for the 13.1 inch you will see he optimized the performance for a 6mm exit pupil. Myself, I am pretty happy with my 12.5 inch F/4.06 with the 31mm Nagler and a Paracorr as a richest field scope. It provides a 1.62 degree TFoV at 48x with a 6.6mm exit pupil. I am fortunate in that my pupil still seems to dilate to 7mm and while this is not quite the generous 1.82 degree TFoV possible with Mel's 13 inch, it's close and the value of Mel's pushing the limit depends on the usefulness of that last 18 degrees of AFoV between 82 degrees and 100 degrees.Jon
-DannyMy warehouseMy Channel
Author of "What's Up" articles for CN Author "Touching the Universe" iUniverse Author "Deep Sky Observing" Springer Author "Nebulae and How to Observe Them" Springer 8" Celestron SCT and Vixen ED 80 on a CGEM Canon T2i camera and lenses for piggybacking
Quote:Here is a shot of me with a 6 inch f/5 Newtonian I constructed some years ago