I don't know if this has been asked of you before but, if you were an "average" amateur astronomer like the rest of us and didn't have access to an interferometer, what would you use to test compound instruments for optical quality? I know that some don't care but I like to know the optical quality of my instruments. I have read and re-read your "essays" at: http://voltaire.csun.edu/roland/index.html many times and love the detailed info on telescope performance ( your CCD/MAK photos are flat incredible!) but what can the "average" amateur telescope owner do to know his or her optical quality?
At present I use a 250 line glass grating inside focus showing 4 bands and the out of focus star test to test my instruments. I use the airy disk (when seeing allows)as my final test. It's all I got
At present I use a 250 line glass grating inside focus showing 4 bands and the out of focus star test to test my instruments. I use the airy disk (when seeing allows)as my final test. It's all I got
Scopejunkie
40 year old restored C14 with recirculating cooling w/Skywatcher DOB GOTO Conversion (CPC14)
Synscan DOB mounted Sky-Watcher Evostar 150mm/1200mm ED Refractor
"Rescued" Craig's List Orion 120mm/1000mm Refractor
USAF Vet