Quote:
Originally Posted by thebigasam
Say if i got a really nice eye piece for the 8" Dob would it have a better performance that a 10" dob straight out of the box?
If so, what eye pieces would make the 8" Dob better and have a performance like the 10" for a cheaper price?
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In a word, no! An 8" scope is still an 8" scope regardless which eyepiece you put in it. The differences in performance that you gain with better eyepieces are different to the gains from a larger aperture.
Larger aperture gains in 2 ways. Firstly images are brighter. Secondly, larger aperture allows you to get more magnification. For example in my old 12" I did most of my observing at 67x and occasionally at 115x while in my 20" I do almost all of it at 150x.
With the eyepieces, better quality gives you a larger apparent field of view, or a sharper field of view to the edge, or more eye relief, or less ghosting among others, or a combination of these.
I think confusion sometimes arises in this area because a higher power EP will often improve contrast making dim objects stand out against a darker background, but that is a function purely of the focal length of the EP. Of course, better quality EPs can be easier to use at short focal lengths due to bigger AFOV, more eye relief etc.
Malcolm
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