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Upsize from 1.25 to 2.0 EP's worth the switch?

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#1 steve-in-kville

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Posted 16 February 2013 - 09:59 AM

I am not doing any photos, just viewing. As I am using my Orion I am finding little things here and there that I would like to change. I wear glasses and I feel like larger EP would be helpful, but is it worth the bucks just for viewing?

#2 Eddgie

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Posted 16 February 2013 - 10:41 AM

Hello Steve.

This would be a good question for the eyepeice forum, but to answer your question, a 2" eyepeice itself has nothing to do with the amount of eye releif for use with eye-glasses.

The decision to go to a 2" eyepeice is really more about how much true field you want in your telescope. The 1.25" format limits the size of the field stop of the eyepiece to about 28mm and it is the field stop of the eyepeice that determines how wide a field you can get from your telescope (though the telescope itself may limit you as well).

If the things you are observing fit into the field of your lowest power eyepecie, there really isn't any need to go to a 2" eyepiece.

If you want more eye relief for glasses, you can buy an eyepeice like one from the Baader Hyperion line. These have very good eye relief, are very reasonably priced, and work at either 1.25" or 2".

And this is not the only choice,

So, unless you find that you need a bigger true field, there really isn't any advantage to a 2" eyepeice.

On the other hand, many diagonals shipped with small refractors are not the best in the world (though most are better than people tend to say) and if you ever decide to upgrade to a 2" diagonal, you can continue to use your 1.25" eyepeices with an adapter.

This of course assumes that your telescope will even accept a 2" diagonsl. Is it equipped with a 2" visual back?

#3 steve-in-kville

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Posted 16 February 2013 - 10:49 AM

I only realised now that we have a EP forum! I'll check there.

#4 steve-in-kville

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Posted 16 February 2013 - 10:55 AM

This of course assumes that your telescope will even accept a 2" diagonsl. Is it equipped with a 2" visual back?


heh... just looked at my spec sheet as I am too lazy to run downstairs... shows my focuser is 1.25 rack & pinion. Guess that puts an end to that!

Time to take this over to the EP forums! Thanks for the help.

#5 Jon Isaacs

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Posted 16 February 2013 - 01:08 PM

This of course assumes that your telescope will even accept a 2" diagonsl. Is it equipped with a 2" visual back?


heh... just looked at my spec sheet as I am too lazy to run downstairs... shows my focuser is 1.25 rack & pinion. Guess that puts an end to that!

Time to take this over to the EP forums! Thanks for the help.


You can upgrade to a 2 inch focuser. If you are lucky, you'll find a used one that fits. But then you will need a 2 inch diagonal.. and a 2 inch eyepiece.

Jon






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