Binoviewers - search for the right eyepieces

[Paz]

I've been using Baader Maxbright II binoviewers for a few months now and getting the hang of them and I'm starting to think about what long term eyepieces would work best. I happen to have the following eyepiece pairs that I have been using...

• 20mm Vixen SLV
• 15mm Plossls
• 12.5mm Plossls
• 10mm Vixen SLV

I use them in various combinations with GPC's (none, 1.25x, 1.7x, and 2.6x) in the following scopes (in order of most used to least used)...

• 102mm f7 refractor
• 127mm f15 maksutov
• 203mm f10 SCT

I've not used them yet with my 350mm f4.6 dobsonian but do intend to when the opportunities arise.

My main conclusions from the 4 pairs I am currently using is that the plossls are great in terms of fine views, low weight, and low cost, but I don't like the short eye relief. Having long eye relief as a criteria has brought me to the following idea...

• 25mm plossls - for the lowest magnification, the binoviewers could take a slightly bigger field stop still but there's not many options that are just right to make the most of the available field stop. I thought 25mm plossls rather than 25mm SLVs as 25mm plossls can be had with 20mm+ eye relief anyway.
• 17.3mm Delos or 15mm SLVs.
• 12mm Delos or 12/10mm SLVs.

I've tried 2 delos (a 17mm and 12 mm) in the binoviewers just to see if I can see a clear field stop in both sides at the same time and it is possible - but I am interested in any comments on how doable it is using Delos in binoviewers. I've read some old threads from the-big-astro-forum-over-the-pond and some say they are fine, some say they are too big.

Are their any other options for binoviewers that have decent eye relief (really meaning 20mm)?

William Paolini's eyepiece book says Denkmeir 14mm and 21mm eyepieces have 20mm eye relief but I can only just fit my nose between the Delos, I can't tell if the Denks would have leave more or less room depending on their ergonomics.

[JTEC]

You might like to include the Morpheus range in your options to consider. Supposedly these were designed with binoviewing in mind. I’ve tried pairs of these and of the Delos, and they both work fine. Both excellent as singles, of course.
For some reason, I’m more comfortable with narrower fields than these for binoviewing. Orthos work well for me, as do the TV Plössls, but it sounds as if you’re looking for more eye relief than these generally offer.  I really like the pair of 18mm Tak LEs that I use, and these have more generous relief. If I could keep only one pair it would be these.

[Space Hopper]

If you are looking for the 'right eyepieces' you really must look at the 24mm  (and 19mm) Panoptics.

The 24s pretty much set the benchmark in performance. They are ideal for low power bino-viewing. Outstanding eyepieces.

19s are similarly excellent as well.

Like you i have looked for years at my 'perfect set' of 4 pairs. More to the point 2 pairs of mid power and high power to go with the Pans.

I've tried 15mm Delites, 14mm Denkmeiers, 13mm Naglers,  14 Delos, 10 Delos,9 mm Naglers, Abbe Orthos 16.8mm, and Docter UWA 12.5

I personally found the Naglers really good, but just that little bit too tight on eye relief. The 9s are too powerful for my dodgy seeing conditions, and thats using decent quality optics.

The Denks are really nice, but i sometimes find eye placement a bit tricky at times, same with the De-lites, but that is really down to me rather than the eyepieces.

I still have the Denk 14s but hardly use them so i will probably sell them. If i had a Binotron 27 they'd be ideal, but i only use  Baader viewers ; i have the Max2 as well and a Mk5.

Like the others i found the Delos too big and unwieldy.

 

Check out APM widefields (on TS or APM)

I've just received a pair of 12s, and am on the order list for the 15s.  The 15s look really nice, and i've heard good reports about them. They also do 10mm, but like the 12s are only 60º FOV.

 

So my current high power pairs are the Docter UWAs 12.5 and the untested APM 12s.

The Docters are an impressive eyepiece indeed, but again they are a bit on the large heavy side.

 

I think eyepiece choice is very much a personal thing, and i'm as fussy as they come, maybe too fussy......😄

 

 

 

 

 

[JTEC]

I agree about the Delos being a bit hefty when paired, so not first choice despite their optical excellence. Also using a TEC140 and Baader Mk V and just for interest, the pairs I have are:

Tak orthos 6, 9,  12.5, Tak LE ortho 18, Sterling (Long Perng) Plössl 20 mm and Edmund RKE 28mm.  Used with x1.7 (giving about x1.5) GPC or x2 Powermate. I’d say the 9mm orthos get most use but if I had to pick one pair it would be 18s and vary the negative lens.

As you say, eyepiece preferences are personal though. 

 

[Paz]

6 hours ago, Space Hopper said:

If you are looking for the 'right eyepieces' you really must look at the 24mm  (and 19mm) Panoptics.

The 24s pretty much set the benchmark in performance. They are ideal for low power bino-viewing. Outstanding eyepieces.

19s are similarly excellent as well.

Like you i have looked for years at my 'perfect set' of 4 pairs. More to the point 2 pairs of mid power and high power to go with the Pans.

I've tried 15mm Delites, 14mm Denkmeiers, 13mm Naglers,  14 Delos, 10 Delos,9 mm Naglers, Abbe Orthos 16.8mm, and Docter UWA 12.5

I personally found the Naglers really good, but just that little bit too tight on eye relief. The 9s are too powerful for my dodgy seeing conditions, and thats using decent quality optics.

The Denks are really nice, but i sometimes find eye placement a bit tricky at times, same with the De-lites, but that is really down to me rather than the eyepieces.

I still have the Denk 14s but hardly use them so i will probably sell them. If i had a Binotron 27 they'd be ideal, but i only use  Baader viewers ; i have the Max2 as well and a Mk5.

Like the others i found the Delos too big and unwieldy.

 

Check out APM widefields (on TS or APM)

I've just received a pair of 12s, and am on the order list for the 15s.  The 15s look really nice, and i've heard good reports about them. They also do 10mm, but like the 12s are only 60º FOV.

 

So my current high power pairs are the Docter UWAs 12.5 and the untested APM 12s.

The Docters are an impressive eyepiece indeed, but again they are a bit on the large heavy side.

 

I think eyepiece choice is very much a personal thing, and i'm as fussy as they come, maybe too fussy......😄

 

 

 

 

 

Thanks for the comments, I'll read up on the APMs. I've heard of the Docters being very good.

[Paz]

3 hours ago, JTEC said:

I agree about the Delos being a bit hefty when paired, so not first choice despite their optical excellence. Also using a TEC140 and Baader Mk V and just for interest, the pairs I have are:

Tak orthos 6, 9,  12.5, Tak LE ortho 18, Sterling (Long Perng) Plössl 20 mm and Edmund RKE 28mm.  Used with x1.7 (giving about x1.5) GPC or x2 Powermate. I’d say the 9mm orthos get most use but if I had to pick one pair it would be 18s and vary the negative lens.

As you say, eyepiece preferences are personal though. 

 

Thanks, I had not thought about the 28mm RKE but it looks like it ticks quite a few boxes - good eye relief, long focal length, not too heavy or bulky, not too much glass, the compromise being afov. Would they be good off axis (not that there is much off axis to be had!).

Tak LEs also look good.

[Louis D]

You might also check in with Denis (the binoviewer guru) about microscope eyepieces that work well.  I regularly use a set of 15x Bausch & Lomb widefields meant for binocular heads on microscopes.  They were designed for just such a usage and are super comfy and reasonably sharp.  Leica and Zeiss have more modern versions that are well regarded.  You do need to use them at f/12 or slower because they were designed for slow microscope f-ratios.

[Space Hopper]

A link to the APM ultra flat fields.

They tick all the boxes.....

Currently backordered though....

https://www.teleskop-express.de/shop/product_info.php/info/p9294_APM-15-mm-Ultra-Flat-Field-Eyepiece--65--field-of-view--barrel-size-1-25-.html

[JTEC]

You’re right, there’s not much off axis to be had! 😂  They’re a bit quirky and known for the famous ‘floating image’ effect.  I like them and they go down well, I find, when showing people things through the scope. I don’t think anyone would suggest choosing them in preference to, say, a pair of 24mm Pans though.  That said, they are the fraction of the price and a lot of fun to use.
The RKE range as a whole has slipped off the radar and something is being lost, I think. These are very sharp, bright and contrasty eyepieces that In the shorter focal lengths work very well on Moon and planets and, apparently, were once very popular in that role. I had the 12mm Barlowed alongside a 6.5 Morpheus, a 6mm ortho and a 5mm XW on Mars a few days ago. All of those eyepieces gave great images with each contributing something of its own character that distinguished it from the rest, including the RKE. 

 

 

 

[F15Rules]

Hi Chris,

I am currently using just two pairs for my Binoviewer, a pair of Morpheus 17.5mm and a pair of old Celestron Halloween 26mm plossls. 

I also use a Baader 2.25x zoom Barlow and a W.O. 1.7x nosepiece to get higher powers: I place the Barlow or nosepiece  into the binoviewer nosepiece, and I believe this is giving me around 3.8 or so times the native so magnification: so, in my FS128 at 1040mm focal length I'm getting c59x at native, or 1040/17.5 x3.8 = c225x.with the Baader zoom Barlow, which is working really well for me on Mars at the moment. The Morphs have around 20mm eye relief.

The Halloween plossls give me 40x at native or 152x with the Baader Barlow. The Plossls have about 25-28mm eye relief.

I know MikeDnight swears by pseudo Matsuyama 30mm or 35mms (Celestron Ultima, Parks Gold, Orion Ultrascopic, Baader Eudiascopic) for low power wide field, and your Maxbrights should accommodate the 30s with little or no vignetting?

If you like the Morphs, then why not also consider for the 12mm slot the Morpheus 12.5mm models, much cheaper than Delos?

Good luck with your choices!

Dave

Edited October 15, 2020 by F15Rules
Additional text info

[Paz]

1 hour ago, F15Rules said:

Hi Chris,

I am currently using just two pairs for my Binoviewer, a pair of Morpheus 17.5mm and a pair of old Celestron Halloween 26mm plossls. 

I also use a Baader 2.25x zoom Barlow and a W.O. 1.7x nosepiece to get higher powers: I place the Barlow or nosepiece  into the binoviewer nosepiece, and I believe this is giving me around 3.8 or so times the native so magnification: so, in my FS128 at 1040mm focal length I'm getting c59x at native, or 1040/17.5 x3.8 = c225x.with the Baader zoom Barlow, which is working really well for me on Mars at the moment. The Morphs have around 20mm eye relief.

The Halloween plossls give me 40x at native or 152x with the Baader Barlow. The Plossls have about 25-28mm eye relief.

I know MikeDnight swears by pseudo Matsuyama 30mm or 35mms (Celestron Ultima, Parks Gold, Orion Ultrascopic, Baader Eudiascopic) for low power wide field, and your Maxbrights should accommodate the 30s with little or no vignetting?

If you like the Morphs, then why not also consider for the 12mm slot the Morpheus 12.5mm models, much cheaper than Delos?

Good luck with your choices!

Dave

Hello Dave, thanks for the tips, the Morpheus doing 17.5mm and 12.5mm would be the right focal lengths for me and they look good on eye relief, size, weight, and cost.

The Maxbright 2 does have a decent field stop which got me thinking around 25mm being the most common plossl longer focal length that would not vignette. I guess I could put a 32mm plossl in one side and just see for myself if vignetting bothers me or not.

I'll do some more reading up as I'm in no rush. I had a brief session on Mars this evening with a 102mm refractor, 2.6xGPC, binoviewers and 10mm SLVs giving a bit over 180x and things were looking good.

 

[astro_al]

I only have 4 pairs of eyepieces, 25mm and 20mm TV Plossls and the 10mm and 15mm APM Ultra Flat Fields which have a larger AFOV and better eye relief at the lower focal lengths than the plossls.

I do prefer the plossls and tend to use them with the 2.6x glass path corrector where I can, but the APM EPs are decent although one (i forget which) has noticeable edge of field brightening when used at night. The 15mm can also easily suffer from unwanted reflections on the eye lens.

I keep thinking about buying other pairs but something always takes priority. I may look at the Takahashi 30mm LEs, the 12mm Pentax XFs or the 24mm Panoptics at some point, but overall I am pretty happy with what I have.

Edited October 21, 2020 by astro_al

[AdeKing]

My most used bino eyepieces are a pair of Vixen NPL 30mm which I find extremely comfortable for H-alpha solar with my Maxbrights and 1.7x GPC.

For nocturnal viewing I don't find the NPLs work so well and so I tend to use a pair of 18mm Baader Classic Orthos and swap the 1.7x GPC for a 2.6x GPC to increase the magnification if needed.

I'd love to buy a second Morpheus 17.5mm like @F15Rules but it's out of my budget at the current time.

The eye relief on the 18mm BCOs might be a bit tight if you've disregarded Plossls on eye relief, but the NPL30s have reasonable eye relief.

Edited October 21, 2020 by AdeKing
Correcting errant autocorrect.

[Paz]

17 hours ago, AdeKing said:

My most used bino eyepieces are a pair of Vixen NPL 30mm which I find extremely comfortable for H-alpha solar with my Maxbrights and 1.7x GPC.

For nocturnal viewing I don't find the NPLs work so well and so I tend to use a pair of 18mm Baader Classic Orthos and swap the 1.7x GPC for a 2.6x GPC to increase the magnification if needed.

I'd love to buy a second Morpheus 17.5mm like @F15Rules but it's out of my budget at the current time.

The eye relief on the 18mm BCOs might be a bit tight if you've disregarded Plossls on eye relief, but the NPL30s have reasonable eye relief.

Interestingly I did try to get a pair of 30mm NPLs around when the lockdown was starting but demand / supply generally went awry and they never materialised (I had the same experience trying to get a pair of 25mm plossls!).

I've read up on the Morpheus and they actually tick all the boxes but finding a pair second hand would be tough.

I've put out a wanted ad for a second hand 17.3mm Delos as I would only need one to make a pair and will see if that turns anything up.

I think I may ditch the idea of any eyepieces shorter that than and keep reading up on something from 25mm-30mm and use barlows/extensions for higher magnifications.