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Prador

EP upgrade options

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Good evening all,

Instead of agonising over potential purchases I thought I'd ask the much better informed people here :). I know this subject is sometimes done to death but I'd rather gather valuable advice before splashing out.

I have a full rack of BST's which I do enjoy using but would like to upgrade these EP's to something a bit more 'special'. I get there's a lot of variables so here's my specific needs/desirables etc:

  • They will be used in a 250mm f4.7 newt and 80mm f7 refractor.
  • I observe both planetary, lunar and DSO's in a light polluted city but occasionally get out to a darker spot on the outskirts of Dartmoor.
  • I wear specs for correction in one eye but not the one I observe with. I do encourage my young son to take part but he cannot observe without his specs on so decent eye relief would be preferred.
  • Budget is £50-150ish per EP. I have no problem buying used as we all tend to look after our shineys.

I catch myself looking at UWA 82 degree EP's but I imagine they come with significant compromises in my price range. I'd probably happily sacrifice a bit of FOV if the eyepiece is sharper. I know I'll not achieve TV standards without digging way deeper but hoping for a reasonable middle ground. 

I really appreciate any advice and/or personal experience

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Hello, 

Good to hear from you.., 

I have no experience with BSTs myself, but I'm curious.., Its not clear if you currently enjoy using these eyepieces with the scopes you mentioned above, but if that is the case, what exactly are you NOT getting out of your current eyepieces that you hope to achieve from future upgrades? 

Thanks., 

Best.., 

bsdsgl84 

 

 

 

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2 hours ago, bsdsgl84 said:

what exactly are you NOT getting out of your current eyepieces that you hope to achieve from future upgrades?

A good point.

I find the BST's introduce more aberrations than I would like. Astigmatism is quite heavy once past the central third of the image and I'd like slightly improved colour correction on high contrast targets. An increase in AFOV would be nice and as wooly as it sounds, I'd like to own a set that just feels a bit more premium.

Thing is I'm not really coming from an informed position as these are the only EP's I've ever owned. I could go ahead and buy an eyepiece or two and see how I get on with them but I'm reluctant to waste mine and a retailers time/money by returning EP's that don't deliver a tangible improvement. 

 

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Hello, 

I understand., thanks for the additional information.., 

Given your starting position coming from BST (which is an EP line from Barska - you may know their in house line called Olivon) and the price point you provided, may I suggest you consider the following lines: - 

  • Baader Hyperion 68° 
  • Explore Scientific Waterproof AR 82°

in terms of edge performance and eye relief.  At your price point, with a focused shopping exercise you may well find some of them brand new as well., 

Feel free to take some time to do a bit of research for them as well, okay? 

Hope that helps.., 

Best.., 

bsdsgl84 

 

 

 

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First, what's your total budget?

Second, which of the BSTs do you tend to use most often?

Third, can your son use all of the BSTs successfully with glasses?

Fourth, how do the BSTs perform in the f/7 scope?  I assume the edge issues are when used in the f/4.7 scope, correct?  The 5mm and 8mm work find at f/6 and above across the field for me.  The 12mm through 25mm have some edge issues at f/6, but starting around 50% out rather than 33% out.

By all reports, the Baader Hyperions do poorly below f/7, so they would be an improvement only in field of view.

The ES-82s do better, but have short eye relief.

I'd probably steer you toward the Baader Morpheus line.  Not as expensive as the Televue Delos or Pentax XW, but very close in performance and with a wider field of view and just as much eye relief.  I have the 9mm and it is terrific at f/6.  I also have the 14mm, and it is just a bit worse at the edge.  The 6.5mm is supposed to as good as the 9mm.  The 17.5mm, 12.5mm, and 4.5mm are slightly behind the 9mm and 6.5mm, but ahead of the 14mm from what I've read.

At 22mm, the Omegon Redline (Celestron Ultima LX, Olivon 70, AstroTech AF70, Arcturus Ebony, Telescope Service Expanse ED, Astromania SWA, etc.) is very good out to 95% of its 70 degree field at f/6 and with good eye relief.  I'd guess it's a bit worse corrected at f/4.7, though.  Keep in mind, it's a 2"-only eyepiece.

The discontinued 22mm Vixen LVW is supposed to be very good in faster scopes and have decent eye relief, but is difficult to locate used.  It is 65 degrees and a 1.25" eyepiece.

Edited by Louis D
typo
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Total budget for 5-6 eyepieces would be around £600 but this would be buying single EP's over quite some time. After a recent loft conversion, any 'unnecessary' purchases come with significant scrutiny 😆

I tend to use the longer focal lengths (12/15/18mm) of the set the most.

As my son is only nine and with a strong glasses prescription he sometimes struggles with eye placement. Blackout is common but that's likely due to his age and a tendency to move around. I do try to explain to him that's likely to happen and once 'on target' he seems fine. Seeing as his glasses are right up to the eye lens would suggest we're operating at the limit of eye relief. The lens on the BST's are slightly recessed even with the eyecup fully down so I'm sure I've already lost 3-4mm of the stated 16mm eye relief.

The BST's do perform better in the f7. In the newt I get a combination of astigmatism and coma; the latter introduced by the scope. To be honest the smaller refractor gets used way more as the 10 incher takes longer to set up. I dont have the space to leave everything set up ready to go so gets broken down after any session. I wouldn't fancy putting that one on the Sabre!

The Baader Morpheus EP's do seem to be mentioned regularly as a highly rated product. I'd have to wait for used purchase opportunities for those. I've always liked the look of ES82's but as you say, no improvement in ER.

I will take a look at some of your other suggestions and I appreciate your time responding with some good advice.

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9 hours ago, Prador said:

I'd probably happily sacrifice a bit of FOV if the eyepiece is sharper.

There is the 25mm Televue plossl that offers 17mm of eye relief and is a sharp eyepiece, with great build quality. I own two and they are very versatile- from seeing the Horse Head, to binoviewing to sharp low power views on the moon and planets. To this I would add a quality barlow such as the Baader VIP,or any other good 2x barlow. The barlow benefits things in a couple of ways including pushing the eye relief out a bit, possibly useful for your son.

Down the road a 2" APM 20mm HDC or the TS equivalent tsxwa 20mm is a super low power eyepiece. The 25mm TV plossl is sharper, with less scatter and will show less perceived coma in the f4.7 newt however.

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Id spend the lot on three Baader Morpheus, starting with the stunning 17.5mm. So, perhaps my choice would be 17.5mm, 9mm & 6mm. :icon_cyclops_ani:

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I agree with Louis D above, the Baader Morpheus would be more suitable for both of you, eye-relief is around 20mm which would suit both of you.  They are quite expensive but do meet your criteria, better to spend a bit more now as they will serve you well in the future.

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It would seem there's a very good reason why the Morpheus doesn't pop up in classifieds that often and when they do they don't hang around.

They are more expensive but tick all the boxes so worth the investment. 

Thank you all for the great advice.

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9 hours ago, jetstream said:

Down the road a 2" APM 20mm HDC or the TS equivalent tsxwa 20mm is a super low power eyepiece.

They would work as very well corrected 70 degree eyepieces with eyeglasses, I suppose.  I would still error toward the 22mm TS-Optics Expanse since usable eye relief would be the same at 70 degrees (with the eyecup removed via unscrewing) and the price and size are much smaller.  Yes, the correction at the edge at 70 degrees won't quite be there compared to the XWA.

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Not sure if this is of interest, but another recent discussion was around wider field eyepieces in your price range.

 

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