The all important star test analysis, SCT.
Posted 11 January 2013 - 01:03 PM
Posted 11 January 2013 - 01:43 PM
Posted 11 January 2013 - 07:18 PM
Posted 13 January 2013 - 11:43 AM
Thanks to both of you!
Posted 13 January 2013 - 01:39 PM
Ill try that next time thank you, do you know if a Roddier test will work with my current start test images?
Probably not. Again, the diffraction effects will be most notable in the slightly defocused images. I prefer Dick Suiter's "breakout" star test where you defocus only just barely enough to observe the very first hints of the central shadow from the secondary becoming visible (the 'breakout' point). Remember that in SCT's, there is often a little residual spherical aberration present even in some halfway decent instruments, so don't panic if you see just a little in the star test. Clear skies to you.