[Nikolas (Nik)]

Originally Posted by Atmos

The diffraction limit is a telescopes ability to fully resolve to point light sources. A good example of this can be with splitting double stars where an 80mm refractor will not be able to cleanly split two stars with less than a 1.45" separation. With a separation of 1.3", two stars could be seen as a misshapen star and the centroids will be separate but the diffraction rings will not be split.

A 130mm refractor has a diffraction limit of 0.89". Your C9.25 has a diffraction limit of 0.5". This is all a function of aperture. Now with the 183 you're getting a pixel scale of 0.33"/pixel but with the 1600 you're imaging at 0.53"/pixel. At this scale you're biggest problem is your seeing conditions more so than whether you're near your C9.25 diffraction limit.

This 1600 is better for the C9.25 as you are at a better imaging scale and the sensor is a big larger.

Thanks for that