57 replies to this topic

[Procyon]

How would you guys rank these eyepieces for viewing Starfields / Milky Way / Asterisms / Nebulae? In terms of color fidelity, contrast, transmission. Looking for a pair for an f/6 and f/7 Refractor. And sometimes an f/10 SCT. I may add H-Beta/UHC/O-III filter to the train at times. My current pairs are 20mm TV Plossls and 25mm Zeiss W/PL 23's.

 

From Don's Eyepiece guides:

 

 

Edited by Procyon, 07 May 2025 - 10:51 AM.

[havasman]

I have a pair of TAO's I like just fine. The only others on your list I've tried were the RKE's and I no longer have those. Binoviewers are used here for Ha solar.

Edited by havasman, 07 May 2025 - 09:59 AM.

[balcon3]

How would you guys rank these eyepieces for viewing Starfields / Milky Way / Asterisms / Nebulae? In terms of color fidelity, contrast, transmission. Looking for a pair for an f/6 and f/7 Refractor. And sometimes an f/10 SCT. I may add H-Beta/UHC/O-III filter to the train at times.

 

From Don's Eyepiece guides:

 

 

You seem to be aiming for focal length around 30mm. Is there a reason? For star fields/Milky Way I prefer wider AFOV eyepieces. Something like a Panoptic 24 would get you the same TFOV with a wider AFOV, which I prefer. For transmission/contrast color my favorite for 1.25 inch format is the Masuyama 16/85 but I don't think I'd recommend them for f/6. The Morpheus 17.2mm has a lot of fans for Milky Way scanning. I use the narrower AFOV eyepieces when the target is smaller, like planets or globular clusters, when I want highest contrast/transparency.

[Starman1]

How about a pair of 32mm Plössls?

I agree, though, a pair of 24mm 68° would be more engaging, and have a darker background sky.

[Procyon]

You seem to be aiming for focal length around 30mm. Is there a reason? For star fields/Milky Way I prefer wider AFOV eyepieces. Something like a Panoptic 24 would get you the same TFOV with a wider AFOV, which I prefer. For transmission/contrast color my favorite for 1.25 inch format is the Masuyama 16/85 but I don't think I'd recommend them for f/6. The Morpheus 17.2mm has a lot of fans for Milky Way scanning. I use the narrower AFOV eyepieces when the target is smaller, like planets or globular clusters, when I want highest contrast/transparency.

I have a pair of 20mm TV Plossls & a pair of 25mm Zeiss W-PL's. Should have included that part in my first post lol. Those would have magnifications and exit pupils of 39x/2.8mm and 31x/3.5mm in a 110mm f/7 refractor. Those two pairs will be used as my main planetary eyepieces in the C11. With and without a barlow lens.

A pair of 32mm TAO's would give 24x, an exit pupil of 4.6mm and a TFOV of about 1.85º. You think I'm better off just going with what I already have instead? For viewing Starfields, the Milky way & Asterisms only.

Edited by Procyon, 07 May 2025 - 01:01 PM.

[Procyon]

How about a pair of 32mm Plössls?

I agree, though, a pair of 24mm 68° would be more engaging, and have a darker background sky.

I tried binoviewing with a pair of 32mm TV Plossls a long time ago, with eyeguard extenders, and very possibly, double eyeguard extenders. They just didn't work out for me, had blackouts and was very uncomfortable using them. I classified it as a wobbler type. But the 25mm TV Plossls I used to have were amazing. 

Edited by Procyon, 07 May 2025 - 05:03 PM.

[RAKing]

The Masuyama 30mm MOP replaced my TV 32mm Plossls.  I use the MOP for solar viewing, because while the actual FOV is slightly less than the 24 Panoptics, it has a brighter exit pupil and was more comfortable to use.

 

I use and love the 24mm Panoptics for most of my wider views with the BV.  They are still the best overall.

 

Cheers,

 

Ron

[betacygni]

From other threads I understand you intend to binoview at native focal ratio (no amplifier), in which case I’d agree with the 24mm Panoptic being the ultimate wide field binoviewer eyepiece. Many other eyepieces I might suggest wouldn’t have sharp stars at the edges of a f6 light cone, including most on your list. The panoptic has one negative though, which is why I prefer more narrow AFOV eyepieces in general. It has very bad geometric distortion (pincushion, like you’re looking through a fishbowl, objects are more magnified at edges) which creates a very bad effect if you pan around the sky with it. If you don’t pan around a lot it’s not noticeable. Some people are bothered by this, others not.

My ultimate binoviewer wide field panning suggestion though is using an amplifier to extend the focal ratio a bit and get two Masuyama 16mm 85* eyepieces. They have minimal geometric distortion and perform very well at longer focal ratios.

Edited by betacygni, 07 May 2025 - 10:36 AM.

[Scott99]

Is f/6-f/7 going to be the focal length with the BV?  Or will there be a 1.25x or other corrector used.  For me f/6-f/7's a little short for the various plossls, I'd probably go with 24mm Pans or something similar.  I have 25mm Claves for this, but my scopes are going to be f/8 or f/9 and most likely used w/ 1.2x corrector as well.

 

The 30mm MOP's or LE's might fare a little better at f/6 than a regular 4-element plossl but won't be flat to the edge like Panoptic.  Normally I"m not a fan of the Pans but they work so well for this purpose, I've had many great views in friends' BVs with the 24mm Pans in there.

Edited by Scott99, 07 May 2025 - 10:40 AM.

[Procyon]

From other threads I understand you intend to binoview at native focal ratio (no amplifier), in which case I’d agree with the 24mm Panoptic being the ultimate wide field binoviewer eyepiece. Many other eyepieces I might suggest wouldn’t have sharp stars at the edges of a f6 light cone, including most on your list. The panoptic has one negative though, which is why I prefer more narrow AFOV eyepieces in general. It has very bad geometric distortion (pincushion, like you’re looking through a fishbowl, objects are more magnified at edges) which creates a very bad effect if you pan around the sky with it. If you don’t pan around a lot it’s not noticeable. Some people are bothered by this, others not.

My ultimate binoviewer wide field panning suggestion though is using an amplifier to extend the focal ratio a bit and get two Masuyama 16mm 85* eyepieces. They have minimal geometric distortion and perform very well at longer focal ratios.

Yes, natively : ) The main scope used will be a 110mm f/7. I've gotten addicted it seems, to refractors lol. Something I thought would never happen! 

 

I thought going with an exit pupil of about 4-4.5mm would be better. I'm used to SCT ergonimics, and I hate exit pupils over 4mm. But with refractors, it looks like I can tolerate an exit pupil of 7.5mm, and this from a bortle 8-9 zone. I seem to like the 3-5mm exit pupil zone a lot though. I don't want to go under 2.5mm. Can't wait to bring this setup to a dark site.

Edited by Procyon, 07 May 2025 - 10:47 AM.

[betacygni]

Yes, natively : ) The main scope used will be a 110mm f/7. I've gotten addicted it seems, to refractors lol. Something I thought would never happen!

I thought going with an exit pupil of about 4-4.5mm would be better. I'm used to SCT ergonimics, and I hate exit pupils over 4mm. But with refractors, it looks like I can tolerate an exit pupil of 7.5mm, and this from a bortle 8-9 zone. I seem to like the 4-5mm exit pupil zone a lot though.

Yes, my eyes make for bad stars above about a 3mm exit pupil. You might even consider something like a 16mm Nagler pair. Smaller exit pupil, but still a really wide true field of view with good edge correction on a fast scope.

[havasman]

If I was going to do what the OP plans to do with his binoviewers I would probably at least give 24Pans a shot. My 24/68 of choice has been the ES and with its wider body profile I was not tempted to get a 2nd. I already had a 32mm TAO so it was a pretty easy choice for me. Plus, as I said, I'm using them for Ha solar. While that's a challenging task for an ep it is different from widefield nighttime observing. I used a 24Pan pair in another's binoviewer in 32" Dob and 100mm APM big binoculars and they were very good, the best of several options available there. But that's been years.

 

My favorite use for the 32 TAO is in the NP101is cyclops from a very dark site. There it shows the tightest, brightest stars I've seen in a scope and is a favorite-ever view. But it is not the widest FOV.

[Procyon]

Is f/6-f/7 going to be the focal length with the BV?  Or will there be a 1.25x or other corrector used.  For me f/6-f/7's a little short for the various plossls, I'd probably go with 24mm Pans or something similar.  I have 25mm Claves for this, but my scopes are going to be f/8 or f/9 and most likely used w/ 1.2x corrector as well.

 

The 30mm MOP's or LE's might fare a little better at f/6 than a regular 4-element plossl but won't be flat to the edge like Panoptic.  Normally I"m not a fan of the Pans but they work so well for this purpose, I've had many great views in friends' BVs with the 24mm Pans in there.

Hi, good question, no correctors or barlows will be used, I want a wide TFOV also.

 

If I ever find a 1.2-1.3x corrector, I'll buy it though, but I don't think it will matter for scanning Starfields and the Milky way.

[betacygni]

The other thing to consider is your binoviewer, many of the cheaper models have relatively small prisms. This might vignette the field stop of ~27mm on 24mm Panoptics or 32mm plossl variants.

Edited by betacygni, 07 May 2025 - 10:54 AM.

[Procyon]

Yes, my eyes make for bad stars above about a 3mm exit pupil. You might even consider something like a 16mm Nagler pair. Smaller exit pupil, but still a really wide true field of view with good edge correction on a fast scope.

I find stars get tighter with lower exit pupils lol. Especially over 4mm. Go figure. I've already tried a pair of 16mm T5 Naglers, definitely not me. 13mm T6 Naglers are good. 

Edited by Procyon, 07 May 2025 - 11:02 AM.

[Procyon]

The other think to consider is your binoviewer, many of the cheaper models have relatively small prisms. This might vignette the field stop of ~27mm on 24mm Panoptics or 32mm plossl variants.

Exactly, why I don't have Pans lol, besides I'm sure the Zeiss W/PL's are better and have a field stop in the range I can use. And yes, my original thought was Brandons or TAO's, with their lower field stops. The thing is the 32mm TV Plossls I once tried, may or may have not vignetted, can't remember exactly, the blackouts bothered me so much I sold them immediately. I think I'm going to get the TAO's, I read Brandons are better or tied for planetary but TAO's are possibly better for deep space. I wanted some more feedback. Thanks guys.

Edited by Procyon, 07 May 2025 - 11:49 AM.

[Bob4BVM]

Some of the pairs I like most for your kind of targets are my Zeiss W/PL 10x/25s,  Leica HC Plan 10x/25s, 28mm RKEs, 24mm Manon 84*s, and best of all the APM 30UFFs, but with a normal BVer i guess that last pair would be off the list.

 

IME the perceived 2-eyed view seems much wider than cyclops, so i don't mind narrower AFoV EPs on most targets. If it's a very wide target like the Veil, Cygnus N7000 complex, M31, etc, then the 30UFFs are my usual goto.

 

For really wide stuff like MW starfields I have a pair of the old original Meade 56mm SuperPlossls, which are amazing if you have a wide enough IPD for the big barrels. Were it not for their super long ER i could not use them, but as it is I can just make them work for my 65mm IPD. But again, those are 2" barrels so not for normal BVers.

 

CS
Bob

Edited by Bob4BVM, 07 May 2025 - 12:04 PM.

[betacygni]

Exactly, why I don't have Pans lol, besides I'm sure the Zeiss W/PL's are better and have a field stop in the range I can use. And yes, my original thought was Brandons or TAO's, with their lower field stops. The thing is the 32mm TV Plossls I once tried, may or may have not vignetted, can't remember exactly, the blackouts bothered me so much I sold them immediately. I think I'm going to get the TAO's, I read Brandons are better or tied for planetary but TAO's are possibly better for deep space. I wanted some more feedback. Thanks guys.

At these levels of eyepiece quality the differences are going to be almost trivial. I’d worry more about comfort. I owned all 3, the 32mm TAO, 32mm Brandon, and 33mm TPL. They were all superb, the Brandon I still own because of comfort and (for me) ease of staying on exit pupil. If you can afford it (easier if buying used) compare them yourself. That’s the only way to know for sure, particularly binoviewing where individual facial structure matters more.

[Procyon]

I'm reading comments from various reliable people, yourself included, and everyone here.

The Taks may go deeper on the faint stuff as Allan Wade said, but that may probably not matter for bino use at 25x. Mike-Sarkikos said the Brandons may have the better presentation on Open Clusters but not the coatings to go deeper. SandyHouston liked the snap to focus on the Abbes more. No mention of contrast differences, from Mike's comment the Brandons may be a little better there, not sure though, he probably hadn't tried the Abbes back in 2013 when they came out. That's an old comment so maybe he'll see this and tell us what's up lol.

What to make of all that? Who knows, everyone's different, but their comments make a lot of sense to me.

Hard choice though, I have a 48mm Brandon and love flat tops and the Brandon view looks so perfectly crystal clear. If I got the 32's I'd prefer that version and use a hood or a bino eye hood thingie from B&H if needed. At the same time, my previous binoviewer's last pair were Tak 18mm LE's and do remember saying these were made for binoviewing with that easy to look through and quick snap to focus feel. The top of the lens and eyeshield of the 32mm Abbe looks very similar.

I'll get what I find and be happy. : )

Edited by Procyon, 07 May 2025 - 01:19 PM.

[Procyon]

Some of the pairs I like most for your kind of targets are my Zeiss W/PL 10x/25s, Leica HC Plan 10x/25s, 28mm RKEs, 24mm Manon 84*s, and best of all the APM 30UFFs, but with a normal BVer i guess that last pair would be off the list.

IME the perceived 2-eyed view seems much wider than cyclops, so i don't mind narrower AFoV EPs on most targets. If it's a very wide target like the Veil, Cygnus N7000 complex, M31, etc, then the 30UFFs are my usual goto.

For really wide stuff like MW starfields I have a pair of the old original Meade 56mm SuperPlossls, which are amazing if you have a wide enough IPD for the big barrels. Were it not for their super long ER i could not use them, but as it is I can just make them work for my 65mm IPD. But again, those are 2" barrels so not for normal BVers.

CS
Bob

Yea, well said on everything Bob. And my limit in terms of comfort with eyepiece width for binoviewing is a bit less than a Radian's 1.8" thickness. Preferably about 1.5". I have middle of the range IPD if I remember correctly. I managed to binoview with 2x 17.3mm Delos once, but that didn't last too long lol.

Edited by Procyon, 07 May 2025 - 12:42 PM.

[T1R2]

Most modern 32mm Plossl's have more ER, however the S4000 Meade SP32 's had a severely recessed eye lens, and those are the only ones I knew of that were not glasses friendly so I don't use them, however they worked great without glasses on, you could stick your eye right up there on them with no blackouts, but they are discontinued so you'd have to find them used, and they were about the 1.5" width you're looking for. 

 

I'd suggest making the slip-on eyecup extenders with a sheet of craft foam from Walmart 

 

 

This one is nice and comfortable with three layers thick, slides on and off whenever I need it. 

1. Cut a length of the craft foam about 35mm width

2. Wrap it to fit end to end, then secure it with a piece of tape

3. Then test its ER, and slice off one little strip 1mm at a time until you get the right height

4. Then add one more layer around the test fitted piece that been accurately cut and glue it on and secure it till its dry

5. Add one layer on the inside, you'll have to measure because it'll be shorter than the other two because its going on the inside and its bottom edge will rest on the top rim of the EP that down inside the tube, these last two layers really add comfort/ thickness

 

my slip on eyecup slides on and stops when it hit the Celestron Omni's rubber grip ring, so its easy to get the right height every time it goes on. 

 

 

 

 

[DRodrigues]

Procyon,

 

Didn't saw the BVs you use...

[Procyon]

Procyon,

Didn't saw the BVs you use...

It's just a simple Arcturus Binoviewer. It weights only 500 grams, clear aperture 23mm I think.

 

Need to stay under 15 lbs for now.

Edited by Procyon, 08 May 2025 - 07:55 PM.

[GGK]

How about a pair of 32mm Plössls?

I agree, though, a pair of 24mm 68° would be more engaging, and have a darker background sky.

That’s what I use for widest field in my binoviewer. I typically pick the 24mm Panoptics without a filter and the 32mm Denkmeier Plossls when using a nebula filter. I do the same whether using the SCT or a fast refractor.

 

Gary

[Procyon]

Interesting that Ernest found the 32mm 44º Tak Abbe Ortho to actually be a 33mm 41º eyepiece, extremally sharp in the center with very high transmission. 

 

32mm Takahashi Abbe Ortho 99 / 97 / 98 (RGB) Meas> 33mm FL, 41.1º AFOV

 

Image quality test results

Plano apochromat 1:5, aberration spot size:
edge of field of view: 20 arc minutes; aberrations: sagittal astigmatism, rhomboid
zone (70%): 12 arc minutes; aberrations: astigmatism with a predominance of the sagittal component
center: 0.8 arcmin; aberrations: single-ring diffraction with traces of chromatic aberration and spherical aberration
central sharpness zone 50%
Distortion: barely noticeable positive distortion of straight lines
Vignetting: not noticeable
Bean Vignette: No
Image coloring: no
Field of view visibility with glasses: 100% (Maybe this will make 25585 happy)
Aperture edge: sharp
Light scattering: none
Dirt between lenses: no
Focused highlights: no

Conclusions and recommendations

An excellently made eyepiece with ideal correction of aberrations in the center of the field of view. In the center, sharpness and contrast are limited only by the observer's eyes. Astigmatism and curvature increase across the field of view, reaching a noticeable value at the edge of the field of view. Effective enlightenment: no trace of glare, minimal light scattering halo. The deeply recessed eye lens is well protected from external illumination. The field of view is very modest (even smaller than stated). A strange puncture with the focal length (33 instead of 32 mm). The eye relief is very comfortable, you can observe even with glasses. If you care about the quality of the field correction, then it is better to use the eyepiece in telescopes of moderate and low aperture ratio (F8-F15) to achieve maximum image contrast. For example, on extended nebulae, maybe with a deep sky filter. But as a 1.25" overview eyepiece, I would look for another eyepiece.

 

Thanks Ernest 

 

Maybe we can send him a 32mm Brandon to try lol.

Edited by Procyon, 09 May 2025 - 09:44 AM.