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Old 19-03-2017, 09:39 PM
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mental4astro (Alexander)
kids+wife+scopes=happyman

mental4astro is offline
 
Join Date: Jun 2008
Location: sydney, australia
Posts: 4,937
Bill,

Alas a scope like yours uses a spherical mirror, not a parabolic one. With its fast focal ratio, it just won't focus well at high magnification. A parabolic mirror will. It is also made very cheaply and the with quality as its paramount interest - this again goes to a degradation of the image. Scopes like yours can provide a good image, but it needs to be within its strengths. A decent plossl eyepiece is better than what these scopes are supplied with, but again they are better than nothing and use them to their strengths with those of your scope and you will get respectable results.

My 76mm FirstScope I know has a poor primary mirror. But for low power work its is fine. Even knowing its limitations, I am still having a good go with it to become more familiar with what it is capable of, and what I can see through its problematic high power image.

I always say "any scope is better than no scope at all". Don't be discouraged. I actually use one of these FirstScope's as a big finder on my 17.5" scope. I use another f/4.4 114mm Newt, also with a spherical mirror, for video astronomy. Again, I'm making use of the strengths of both scopes - low power.

I've just found a set of notes i made after viewing Saturn with my ED80 refractor. It was late in its season, so it was far from its opposition best. But I still did manage to see the Cassini division with it. Something that absolutely amazed and thrilled me!

Alex
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