Quote:
Originally Posted by kimmik
The properties i mentioned, like spherical aberration of the exit pupil, and weight for example are intrinsic to the eyepiece and not dependent on the scope.
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Those properties may arguably be better in a 25mm Plossl, but the notion you infer - that as such, they make it a better eyepiece in any telescope - does not follow.
In f/9 telescopes like you have, a 25mm Plossl gives a 2.8mm exit pupil, which is fine for brighter DSOs, but slightly suboptimal for the very faint ones.
In an f/4.5 dob, yes, a 25mm eyepiece will give nice eye-popping bright images of bright DSOs, but it will be extremely suboptimal for identifying and seeing anything interesting in very faint DSOs.
In my C8, for years my favourite eyepiece was a wide angle 20mm Erfle. On the negative side, it had lousy eye-relief and very poor edges compared to my 26mm Plossl. On the positive side, time and again I was easily able to spot and get good views of very faint galaxies with hardly any effort, compared to the 26mm Plossl.
Regards,
Renato