Just a note for anyone considering an erecting Diagonal
I am getting a 72mm Ed Skywatcher to attach my Quark Daystar filter for solar work.
Thinking that it will make a decent carry about scope, birds, terrestrial etc I decided to but an erecting diagonal, Ostara.
Now I appreciate that there are GOOD ones out there but for what I want it for £80 was a decent price, and as stated in the adverts it is a "Ostara 2'' 45 degree Erecting Prism for Telescope with 1.25'' Adaptor" on Amazon.
IT IS NOT A 2" DIAGONAL, BE WARE, in fact I paid £50 on Ebay so happy but it is NOT as described.
It is in fact a "Diagonal capable of accepting 2" eyepieces and NOT a 2" diagonal".
As a buyer and contracts officer I have always been ware of such "CONS".
If you look at the images you will see that my dialectric diagonal has a FULL 2" of CLEAR aperture, where as the Ostara is "stopped down" to 1.25" allowing for the fixing of the "prism" rather than a mirror, which is fine but really limits FOV and light gathering.