Quote:
Originally Posted by mental4astro
There's one thing that is critical to understand about telescopes and eyepieces in oder to make the best choice for YOUR scope - optical matching.
This starts by understanding that all telescopes produce a CURVED focal plane, not a flat one. We are made to think that a telescope focuses to point. This is true only for a single star. But there are stars all across the field of view. When all the stars are plotted at focus across the focus of a scope, you will find that they are spread across a bowl shaped plane. The bowl can be either convex (for refractors, SCT's and Maks) or concave (Newts).
The second part is that it is easier to design EPs for a convex focal plane, and cheaper to manufacture. The concave focal plane of Newts is much more difficult and expensive to design and manufacture EPs.
This is why Naglers, Ethos and the high end Explore Scientific EPs are significantly more expensive than other EPs - these are desinged for Newts.
Match the EP to the scope and you will end up with an image with minimal or no aberrations.
It is when you put an EP designed for the opposite shaped focal that things CAN go pear shaped very quickly with a wide array of aberrations visible, such as astigmatism, field curvature, chromatic aberration, etc.
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Thanks so much for this info! I had no idea I needed to match the scope with the eyepiece. Phew, glad I asked otherwise I might have spent some serious money.
So I might have to bank a bit more cash before I go looking for my next eyepiece...