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Wide Angle Eyepiece

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#1 billisnice

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Posted 22 March 2023 - 08:23 AM

I was going to buy my son a couple better eyepieces for his Orion Funscope. Will the wide angle eyepieces work? Maybe they may not display wide but if he upgrade his scope he would be set.



#2 firemachine69

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Posted 22 March 2023 - 08:33 AM

There's going to be visual aberrations (like seagull-shaped stars), but yes, so long as they have a 1.25" barrel.



#3 Ernest_SPB

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Posted 22 March 2023 - 08:46 AM

Will the wide angle eyepieces work?

 

Yes, they will. 

For this F4 scope you can buy not a most expansive WA eyepieces.



#4 Jim Davis

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Posted 22 March 2023 - 09:31 AM

If you want wide field, one of these would work. The edges of the field of view probably won't be sharp. https://agenaastro.c...a-eyepiece.html


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#5 SeattleScott

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Posted 22 March 2023 - 11:02 AM

A wide angle eyepiece that will be sharp in that scope will cost more than the scope. You can go wider, but you are just gaining abberated field of view. Now potentially one might be okay with framing targets with seagulls in order to get wider view and more context. It just depends, does one want a narrower view but reasonably sharp, or a wider view that isn't sharp? Some are annoyed by the distortions and want a narrower view to cut off the ugly stars. Others are good at ignoring the distortion and like the wider view for framing. It doesn't hurt to try one and see, but I would just buy one first to see how bad it is, rather than buying a set that might not get used.


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#6 Mike B

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Posted 22 March 2023 - 11:59 AM

I was going to buy my son a couple better eyepieces for his Orion Funscope. Will the wide angle eyepieces work? Maybe they may not display wide but if he upgrade his scope he would be set.

I went web-shopping for examples of what an aberrated widefield view might look like in a scope like your son’s… had a hard time coming up with much: https://www.eckop.co...ittal-Foci.png 

Perhaps others have links that more clearly depict the effects?

 

But I’d definitely say “ditto” to Scott’s advice above! Going one-at-a-time, perhaps limiting to eyepieces (“EP’s”) offering a 65-68 degree field?… going much wider may not prove fruitful.
 

You might also ask this question over in the telescope forum, of the scope type your sons Funscope is (Newtonian Reflector?), to see what EPs people are most enjoying with it!?



#7 pj_thomas

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Posted 22 March 2023 - 12:36 PM

32mm Plossl is the widest true field of view (TFOV) for 1.25" focuser.  It will give about 50° apparent field of view (AFOV).  If you want to go to 68° AFOV you could get a 24mm eyepiece that covers the same TFOV as the Plossl, though I don't know many affordable eyepieces.  An more affordable option is a 25mm Paradigm/Starguider which should give a 60° AFOV.  It's a decent eyepiece without breaking the bank.


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#8 star acres

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Posted 22 March 2023 - 04:34 PM

I wouldn't buy anything higher than 20, but high magnification will have it's limits, too. 



#9 sevenofnine

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Posted 22 March 2023 - 06:48 PM

This SvBony 32mm plossl should work well for him. Good luck! borg.gif

 

https://www.amazon.c...e/dp/B07WKCJCWC.


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#10 quercuslobata

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Posted 23 March 2023 - 04:15 PM

At f4 at 32 mm eyepiece is going to give an 8mm exit pupil which I think will show the shadow of the secondary, but will be at least washed out. I had one of those once and think 20mm was as big as I used because of light pollution. Even a 20mm plossl is over a 3 degree field of view, and the 5mm exit pupil might be more usable.


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#11 CrossoverManiac

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Posted 25 March 2023 - 09:48 AM

Eyepieces with too high of a AFOV will have you dotting your eyes dotting from the center to the corners of the eyepiece and I would rather have most of not all of the image in the same field of view (of your eyes looking through the scope). Now other people don't mind that and love having a 110° AFOV. I would recommend trying an eyepiece with a AFOV of 60° first. And someone here mentioned the issue with low powered eyepieces and exit pupil. Apparently, an 8mm exit pupil is not so bad, but even if you were a stickler for not going over 5mm, it would not be so bad to have a 32mm and to use it as a finder eyepiece. The Svbony 32-mm has an AFOV of 46°, which would give you a 4.9° true FOV. I use 38-mm Q70 that I got for a Messier marathon and it's been a big help with finding DSOs.


Edited by CrossoverManiac, 25 March 2023 - 09:49 AM.

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