14 replies to this topic

[Alan S]

Recently, as my eyes are showing signs of aging,  I’ve taken to binoviewing. I am using a Baader Maxbright II and a 1.25” T2 Zeiss spec prism diagonal with a 1.7x GPC.  I’m currently using these with both my Takahashi TSA-120 and an FC-100DF, however, I am awaiting a TEC 140 f/9.6 later this year.  The TEC is natively BV friendly and will likely not need the GPC to reach focus.  I'm looking for some suggestions about eyepieces.

 

If you were starting from scratch with the above BV/diagonal, and had the TEC 140 f/9.6 coming, what eyepieces would you purchase?  I’d appreciate suggestions considering the following criteria:
Eyepieces should be readily available
Comfort is important to me and while I do not use glasses at the eyepiece, I do want to be able to see the full FOV without having to press my face into the eyecup or get eyelash oil on the lens.
I will use the BV’s for everything (DSO observing, some double star work, and the usual lunar and planetary suspects)

 

Here are the eyepieces I have been using and what I think about them:
30mm Celestron ultima series (the original ones), easy to use, good enough, not convinced the overall image is as good as the TV plossls below
25mm Televue Plossl, easy to use, overall an excellent image.  I reach for these 95% of the time over the 30mm ultimas
15mm Celestron ultima series (the original ones), very tight eye relief, seem to deliver a pleasing view, however difficult to appreciate the full FOV due to tight eye relief
7mm Televue Delite, had to “decloak” them to allow use with my narrow IPD.  Image is good however not as easy to hold position with the uber wide eye lens

 

 

Hope that provides enough background (or too much!) for eyepiece recommendations.

Cheers

[havasman]

I recently began using binoviewers and, drawing on posts from years ago, looked around for less widefield eyepieces than I use in cyclops mode. I found the Vixen SLV line hit a lot of marks for me. They are very good simpler eyepieces with excellent twist-up eyecups that allow their 20mm eye relief to be adapted for those like me that don't favor long ER so they are very comfortable. They're less expensive than many lines and are available from Explore Scientific US. Agena may also have some in stock. Vixen has, I'm pretty sure, discontinued the line but what's out there has worked well for me and I'm sure they are still available in several focal lengths from reliable on-line vendors. The Vixen NPL's were much less satisfactory for me, entirely due to their less workable ergonomics.

 

I also managed to pair up my also discontinued Tak Abbe Ortho 32mm and those are my favorite large exit pupil pair. Sorry, I know you want easily found but it's part of my experience with pairs. If I was not yet satisfied with my pairs I'm pretty sure I'd try the new Tak TPL's next. But luckily I am satisfied.

 

But then I kept reading posts from well respected forum members about how the 13T6 Nagler has become their favorite ep pair for BV use and I have long loved the one I have. So I paired it up and now those get the most focuser time for my uses. 

 

I hope this is more helpful than confusing.

Edited by havasman, 02 March 2025 - 01:55 PM.

[Alan S]

Thanks, that is helpful.  I have a set of the Vixen LVW's and also the Vixen HR's, and always liked their eyepieces.  I just may give these SLV's a try!

[havasman]

Thanks, that is helpful.  I have a set of the Vixen LVW's and also the Vixen HR's, and always liked their eyepieces.  I just may give these SLV's a try!

If you like the very fine LVW's you might be able to catch one via classifieds to try a pair in your BV's.

[Kunama]

I have the Zeiss PrimoStar binoviewer and the Baader MB II and use only Tak LE eyepieces with both of my refractors.

The LE are 52 degree AFoV and that works just fine for my needs.  For any mono viewing I switch to the fantastic Leica Asph Zoom and matching Leica 1.8x extender…

 

the Baader binoviewer requires the use of a GPC to reduce colour error induced by the prisms.

[Reid W]

I recently added a Binotron, and it came with the 21s and 14s.

 

if you can find a mate to your LVW 13, that would be a (potential) fantastic setup.

 

The Denk 14s with the eye relief and f.o.v.  give great views, and I would think your LVW would give the same satisfaction.    I did have a set of Hyperions but those have been replaced by the Morpheus lines, but I did once have the LVW 13, sold it my poor decision hasty days.

[Kutno]

But then I kept reading posts from well respected forum members about how the 13T6 Nagler has become their favorite ep pair for BV use and I have long loved the one I have. So I paired it up and now those get the most focuser time for my uses. 

 

 

[balcon3]

I have a Tak FC100DF and Maxbright II. My favorite eyepieces in the Binoviewer are Masuyama MOP's, especially the 16mm/85 and the 12.5mm/53. The 10mm/85 is also excellent optically but a little tight on the eye relief for me when used in the binoviewer (it's fine for me monoviewing). I don't wear glasses and people who need a lot of eye relief would probably not do well with this line of eyepieces. But if you can use them, the degree of contrast and transparency is remarkable. They are not sharp to the edges in faster scopes, but In a 140/f9.6 refractor they should be stunning. They can be bought at quite reasonable prices from Kyeoi Osaka in Japan. By the way, the FC100DF works fine without a GPC, although I usually use one to get to higher mags on planets. 

Edited by balcon3, 04 March 2025 - 04:41 PM.

[radiofm74]

I'm new to the experience and still working out what works for me:

- So far I've used Vixen LVs (the old ones, which are a pain to source but I had them already, so…) and they're great: light, ergonomically perfect, and I can merge well up to fairly short EP focal lengths. Generous eye-relief, and full field at a glance. SLVs will be just as good from what I read.

- Looking for maximum field, and failing to find an LV 40 on the market to match mine, I've experimented with the Baader Plössl 32s and they're pretty great in this application, with the little "outside wings" shielding external light on both eyes. I have the feeling that two "Baader Q-Turret sets" (32 - 18 - 10 - 6… perhaps skipping the 6s) would make another great, lightweight, easily available, budget-friendly set. Less eye relief, though, in the shorter focals, and not great off-axis. 

- One of my favorite eyepieces of all times is my dainty Panoptic 19… less field than the 24 (and for that reason it has less focuser time) but a certain optical je ne sais pas quoi. In my mono set it's a little "squeezed" between Pan 24 and Nagler 16, so I've found a twin at an attractive price and now have a top-tier low power / wide field pair, at least for my shorter refractors. I'm paying the cloud penalty, so can't say… but am pretty sure that for low power Pan 24s or 19s are top drawer. And priced accordingly!

 

Let us know what you find eventually!

 

PS: a bit jealous of your refractor stable ;D Jeeez… the views through that TEC will be something!! 

[Alan S]

I’m still experimenting, although a short burst of late winter weather here has interfered 

 

one thing, I mistakenly wrote in my first post is that I am using 15 mm Ultimas, which is not the case.  They are in fact 15mm axioms, and I’m starting to appreciate them a little more.

 

I purchased a pair of 13mm Naglers off the classifieds, and I’m having a hard time loving them in bino use.  One thing I never appreciated is how much longer the chrome barrel (which has lenses in it) is on these eyepieces.  I had to install some O rings on them so that I could fully seat them in the holders and get them both in focus.  (Without the O rings, I have to fully raise the individual diopters to insert the eyepieces and then do not have enough range to focus both sides). I will probably sell these unless I start to appreciate them more this lunation.

 

I have the 7mm delites, decloaked, and with some after market rubber eyecups they do the job on the nights that seeing is decent enough.  I’ve had some nice views of Mars with them.  Given I really do not need a wide field at this magnification, I may try something else, with better eye relief than say a short FL plossl.

 

So right now, I am happy with the TV 25mm Plossls and considering either the Takahashi 18mm TPL or Baader 18mm classic orthos as the next step up.  There is quite a difference in price and am wondering how much better the TPL would be in general use.  The 16mm Masuyama are also in my mind.

 

The journey continues.

[denis0007dl]

I’m still experimenting, although a short burst of late winter weather here has interfered 

 

one thing, I mistakenly wrote in my first post is that I am using 15 mm Ultimas, which is not the case.  They are in fact 15mm axioms, and I’m starting to appreciate them a little more.

 

I purchased a pair of 13mm Naglers off the classifieds, and I’m having a hard time loving them in bino use.  One thing I never appreciated is how much longer the chrome barrel (which has lenses in it) is on these eyepieces.  I had to install some O rings on them so that I could fully seat them in the holders and get them both in focus.  (Without the O rings, I have to fully raise the individual diopters to insert the eyepieces and then do not have enough range to focus both sides). I will probably sell these unless I start to appreciate them more this lunation.

 

I have the 7mm delites, decloaked, and with some after market rubber eyecups they do the job on the nights that seeing is decent enough.  I’ve had some nice views of Mars with them.  Given I really do not need a wide field at this magnification, I may try something else, with better eye relief than say a short FL plossl.

 

So right now, I am happy with the TV 25mm Plossls and considering either the Takahashi 18mm TPL or Baader 18mm classic orthos as the next step up.  There is quite a difference in price and am wondering how much better the TPL would be in general use.  The 16mm Masuyama are also in my mind.

 

The journey continues.

Hi Alan,

 

I heard you about Nagler long barell, but did you try remove rubber eyeguards on them?

 

They become then simply stunning binoviewers eyepieces. I even dont touch eyepieces at all in that scenario, and enjoying in full 82 deg FOV.

 

Also, latest run I find deff bit better optically than previous optically, and latest run also finally dont have thousands of tiny sleeks/scratches on lenses like previous runs had, and latest run is MUCH MUCH cleaner between lenses.

 

Also, latest run feels less warm as well in colour tone.

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[noisejammer]

I would still use a GPC to correct for spherochromatism created by the binoviewers. Let's say you pick the 1.25x. The effective focal length will be 1344x1.25 = 1680 mm. This translates to f/12.

 

My experience is that I need the exit pupil to be about 0.65mm (or larger) when binoviewing. This means I would pick the shortest eyepiece focal length as 12 x 0.65 =  7.8 mm. Call it 8mm for simplicity. The primary issue is that your binoviewer IPD becomes extremely critical when the exit pupil is small.

 

Almost all eyepieces will work fine at f/12 (the exceptions being those that are designed with built in coma correctors.)

 

My IPD is 76 mm so my selection of eyepieces might be very different to the OP's but I find the Type 5 & 6 Naglers work well as do Docters and the APM equivalent. For low power, I have 30mm Tak LE , 24 Pans and 22 LVW. The LE and LVW may be difficult to find. I'm unimpressed by the APM UFF series but I suppose they are fair value for money.

[bokemon]

Of the ones I've used:

Morpheus - best image quality, but somewhat "difficult" to look thru.  I am not sure exactly what it is - maybe most sensitive to eye placement.

Delite - barely worse image quality (But still very good), but generally well corrected all the way to the edge, and easy to look thru.  Overall favorite.

APM UFF series - easiest to look thru, but tends to show field curvature and some other edge effects at F/5.x.  Oh, but you have an F/9.6, so these should work well enough.

[wrvond]

Having tried my AT150 EDL with the removable section ;in place and removed, I've settled on leaving it in place when binoviewing. As noted, a GPC is still recommended to reduce spherochromatism, plus with the section removed, the focuser tube has to be extended further to achieve focus. I prefer keeping my drawtube as short as possible. 

Also, there are times when I do want to mono view and having to remove the focuser to remove the tube or put the tube back in becomes a pain. The focusers on scopes of this size are rather heavy and threading them in and out gets tiresome at best.

Once upon a time I had several bino pairs of Tele Vue eyepieces - Plossls, Naglers and Panoptics. I got rid of pretty much all the pairs (I've still got a pair of 20mm Plossls) and have shifted over to a pair of Baader Mk IV zooms.

The zooms are not perfect, but they do check a lot of boxes. I also did a direct comparison between the zooms (set at 20mm) and the TV 20mm Plossls. Thinking the lesser amount of glass in the Plossls would give them an edge I was surprised to find I preferred the view in the zooms. 

In the back of my mind I'm still telling myself that less glass has got to be better, so I have been considering the Masuyama's but haven't felt a burning need to abandon the Baader zooms.

 

 

[betacygni]

Having tried my AT150 EDL with the removable section ;in place and removed, I've settled on leaving it in place when binoviewing. As noted, a GPC is still recommended to reduce spherochromatism, plus with the section removed, the focuser tube has to be extended further to achieve focus. I prefer keeping my drawtube as short as possible.
Also, there are times when I do want to mono view and having to remove the focuser to remove the tube or put the tube back in becomes a pain. The focusers on scopes of this size are rather heavy and threading them in and out gets tiresome at best.
Once upon a time I had several bino pairs of Tele Vue eyepieces - Plossls, Naglers and Panoptics. I got rid of pretty much all the pairs (I've still got a pair of 20mm Plossls) and have shifted over to a pair of Baader Mk IV zooms.
The zooms are not perfect, but they do check a lot of boxes. I also did a direct comparison between the zooms (set at 20mm) and the TV 20mm Plossls. Thinking the lesser amount of glass in the Plossls would give them an edge I was surprised to find I preferred the view in the zooms.
In the back of my mind I'm still telling myself that less glass has got to be better, so I have been considering the Masuyama's but haven't felt a burning need to abandon the Baader zooms.

Screenshot 2025-04-13 132343.jpg

Screenshot 2025-04-13 132427.jpg

Another option I’ve used on my bino friendly scopes is to always keep the extension removed and just use regular 2” eyepiece extensions. I’m not super fond of the look, but it’s practical if you go for no amplifier views often (I don’t really anymore). Removing eyepiece extensions is quick and easy vs unthreading.

While I do think some eyepieces perform better than zooms, I’ve come to he conclusion that I should just have a general observing comfort and convenient set (zooms good candidates), then a “high performance” set for nights of really good seeing, or when I’m trying to push observing limits vs just out to enjoy myself and relax.