Help for star test results!Posted By Timothy McDougall |
I think I know what I have to do, but I dont want to jump the gun. Just took delivery of an import "apo" refractor. On star test with vega at zenith,160x, inside of focus nice pattern, outside rings obscured(more turbulence seen outside of focus?)similar to rough surface. Also inside of focus astigmatism obvious on opposite sides of view but none seen outside of focus??? Wouldn't astigmatism appear on both sides of focus and in the center of the view, not just at oppposite edges??? It appears that in a daylight terrestrial view there is vignetting all around the edge, more so where the astigmatism showed up on star test. What is the diagnosis? I had just a short time to do the star test as clouds moved in, I didnt get an overall general look at a field of stars. What level of quality should I accept from the "imports" toted as APO? I think I need to send this back...any help or advice greatly appreciated!
P.S. Televue eyepieces and everbright used!
P.S. Televue eyepieces and everbright used!