With my new AG optical 12.5 iDK I'm getting interested in collimating and checking the optical quality. Got a howie glatter laser collimator with concentric ring beam splitter and the thing works great. Collimated my primary and secondary well.
The conentric rings shoudl be spaced equally and with this telescope design, that would mean the primary mirror would be spaced correctly from the secondary. But it's not very accurate in these regards. So now I'm looking at Ronchi testing. Does anyone know how to do this?
There's this easytester which really looks like a ronchi screen in from of an eyepiece. Looks like you could get an artificial star and move it around the Field of view and check the various part of the telescope.
Seems like it would take a long time to assess the quality of the telescope overall.
It would be nice if there were a big ronchi screen available and just overlay it on a flatman. That would be the ideal. Take CCD pictures and know your optical image path for sure with your CCD.
Charles Dunlop
With my new AG optical 12.5 iDK I'm getting interested in collimating and checking the optical quality. Got a howie glatter laser collimator with concentric ring beam splitter and the thing works great. Collimated my primary and secondary well.
The conentric rings shoudl be spaced equally and with this telescope design, that would mean the primary mirror would be spaced correctly from the secondary. But it's not very accurate in these regards. So now I'm looking at Ronchi testing. Does anyone know how to do this?
Jun 2, 2013
Charles Dunlop
There's this easytester which really looks like a ronchi screen in from of an eyepiece. Looks like you could get an artificial star and move it around the Field of view and check the various part of the telescope.
Jun 2, 2013
Charles Dunlop
http://schmidling.com/ez-testr.htm
Seems like it would take a long time to assess the quality of the telescope overall.
It would be nice if there were a big ronchi screen available and just overlay it on a flatman. That would be the ideal. Take CCD pictures and know your optical image path for sure with your CCD.
Jun 2, 2013