Stop it down with an aperture mask by 1/4 inch increments and see what happens, and
do the same with obstruction mask, if that was used.
No mask was used. I'll try some out.
was it cooled enough?
but either the atmosphere or acclimation is causing too much turbulence.
and if you want to see zones you have to defocus a lot more.
It was acclimated. Probably a combination of turbulence and slightly rough optics?
When a scope has a mixture of theses errors its difficult to evaluate visually. IIRC Suiter recommends defocus of +-15 waves for this particular mixture, but I remain fairly skeptical it can be done well. When you have a mixture of aberrations I recommend using the WinRoddier program or the WavefrontEstimator (Mike Schuster's script) included in PixInsight. This requires a linear detector and more defocus on the order of 20 waves.
A cell phone has on board level adjustments as well as sharpening which makes any analysis problematic.
Is this a Maksutov?
I'll give more defocus a try. You're right a cellphone isn't the best for recording an accurate image, but I'm limited in what I have to work with. It is an SCT, but I intended this to be an exercise in star testing, not so much a telescope critique.
Thanks to all for your input so far.
Edited by Boom, 19 March 2019 - 12:19 PM.