62 replies to this topic

[salishstars]

I recently tried a friend's Masuyama eyepieces and was really blown away by their sharpness and transparency. I am looking at the different eyepieces they sell from the 53° to the 85° versions. There are so many different focal lengths that I wanted to see what the Masuyama fans here like to use most as I am having trouble deciding.

 

I have a C8 @ f/10, a f/15 Mak, and an older 4" f/15 Unitron (not including my f/6 refractor due to fast f ratio which might not be ideal for use with these eyepieces).

 

What are your favorite Masuyama eyepieces and which ones would you recommend? Thank you!

[helpwanted]

32mm 85*, simply amazing!

 

of course, only for a long focus scope, like the ones you list.

[dothead]

60mm  46°, perfect for low-power views at f/15

[Mike B]

I recently tried a friend's Masuyama eyepieces and was really blown away by their sharpness and transparency. I am looking at the different eyepieces they sell from the 53° to the 85° versions. There are so many different focal lengths that I wanted to see what the Masuyama fans here like to use most as I am having trouble deciding.

 

I have a C8 @ f/10, a f/15 Mak, and an older 4" f/15 Unitron (not including my f/6 refractor due to fast f ratio which might not be ideal for use with these eyepieces).

 

What are your favorite Masuyama eyepieces and which ones would you recommend? Thank you!

Might  not be “ideal” at f/6, but I enjoy them anyway! On-axis they’re killer! Beautifully transparent with stark contrast. Yes, stars show notable aberration in the outer 10-15* of the 85’s, but they’re still obviously stars for field orientation!

 

My personal favorite in the 85* series is undoubtedly the 20mm (2-incher), followed closely by their 1-1/4” 16mm… these fl’s produce very productive exit.pupils, lifting faint DSO’s out of the black!

[salishstars]

Have any of you tried the 2" 26mm with the 85° fov?

[salishstars]

When people talk about "MOP" in terms of Masuyama, what are they referring to?

[balcon3]

I have 26mm/85, 16mm/85 x 2, 12.5mm/53 x2, 10mm/85 x 2, and 7.5mm/53. I have several favorites, for different use scenarios. I use them both in my Mewlon 180c f/12 and Takahashi FC100DF f/7.4, sometimes with binoviewer, sometimes mono. I love the 26mm/85 for wide field viewing. The 16mm/85 is my favorite for binoviewing and also used a lot in mono for open cluster viewing. The 12.5/53 is perhaps the finest of the group optically in my opinion. Planets and the moon are stunning in a binoviewer or Barlowed in mono view. I have compared the 12.5/53 with my Morpheus 12.5. No doubt that the Morpheus has a wider, better corrected field to the edge. But stars in the Morpheus look muted in comparison to the Masuyama. All the Masuyama 85's show significant distortion in towards the edge in my f/7.4 refractor. But that doesn't bother me in most cases (as long as the object is contained within the sharp zone of the eyepiece), since I focus on the center of the field where the contrast and clarity are superior to all my other eyepieces. Another thing I like about all the Masuyamas is the eyecup design. It is very soft rubber that is very easy to view with. Regarding eye relief, I don't view with glasses, and all my Masuyamas have adequate eye relief for me in mono mode. The 10mm/85's in binoviewer mode are a bit tight for me. I have no idea what MOP stands for. Some have suggested Masuyama Ortho Plossl, whatever that means. But it is important to note that the MOP's (whether 85 or 53 or 46 degrees) are the newer eyepieces. There are older Masuyamas that are not MOP's, such as the Masuyama Genuine Abbe Orthos.

 

Since you are working at f/10 or above, I think I would recommend the 16mm/85 and the 26mm/85. Both should be fantastic in your scopes. In the f/10 there will be some aberrations at the edge, so don't expect a perfectly flat field. But in my opinion what you gain in contrast and transparency is well worth it. In the f/15's they should exhibit virtually no aberrations. 

[The Cloud Gazer]

I love them all 

 

After trying the 30mm 53°, I got some more, then some more, and then some more, and then... Both the 85° and 53° lines are outstanding. The 50mm 53° is one big masterpiece.

 

The only one I did not get along with and sold it was the 10mm 85° because of the combination of short eye relief and large afov. But that's a personal thing due to my eye biology, many people who love it. Strangely the 5mm 53° is fine for me in comparison. 

Edited by The Cloud Gazer, 25 March 2025 - 04:33 AM.

[Far Star]

Over the last 60 years, I have had well over 200 eyepieces in total - including TV Ethos, Nagler, Panoptic and DeLite as well as Pentax XW, Noblex 12.5 mm UWA, APM XWA 9 mm and 20 mm, Zeiss Orthos and ZAO I, TMB Monocentrics, Takahashi TPL etc., among many others. I had the 32 mm 85° Masuyama and now have the 16 mm 85° and the 20 mm 85°. Of all these more than 200 eyepieces, I have a clear favorite: the 20 mm 85° Masuyama, which I use with my Mewlon 180C (F12).

 

The wonderfully small and lightweight 20 mm 85° Masu has an extremely pleasant viewing behavior (comfortable eye placement) and offers a very bright, brilliant, sharp and high-contrast image over a large part of the easily surveyable field of view. But there's more: observing with this eyepiece is particularly "immersive"; with no other eyepiece have I had the feeling of "immersing myself in space" to this extent and seemingly perceiving my surroundings in three dimensions. In comparison, a TV Ethos offers an even larger field of view and better edge sharpness, but at the same time a less brilliant, less "lively" and somehow boring image. In addition, an Ethos with a comparable focal length is much larger and heavier.

 

The 16 mm 85° Masu is also an excellent eyepiece. However, due to the shorter eye relief, the eye placement - at least for me - is not as comfortable as with the 20 mm 85°. I sold the 32 mm 85° Masu because I can no longer use it properly due to my eye astigmatism (I always observe without glasses, and the Dioptrx do not fit the Masuyamas).

[mountain monk]

I have the 20mm, 26mm, and the 32mm 85* eyepieces. I recently described the view as “elegant,” compared to the 30mm UFF, the classic 31mm Nagler, and the 22mm Nagler. I use the latter two in my Dob and my NP-101. I use the Masus in my other refractors and my C8. I liked the 16mm but there was not enough eye relief for me. Those fuzzy edges… At f/8 in my Tak DZ, they are not a problem. I can’t see those edges anyway unless I bend my neck to “look around the corner” which I am not inclined to do unless I have to. I prefer looking straight through, the direct presentation. In addition, they are physically beautiful, the most downright handsome eyepieces I’ve ever seen—though some people seem oblivious to such matters. Try one and I bet you’ll buy another. My favorite? The 20mm.

 

Dark, clear, calm skies.

 

Jack

Edited by mountain monk, 25 March 2025 - 03:41 PM.

[Mike B]

When people talk about "MOP" in terms of Masuyama, what are they referring to?

As far as I’m understanding it- yes, MOP is short for Masuyama’s Orthoscopic Plossl, whether of an older vintage or the newer 53* line. However, the MOP designation is NOT applied to their 85* series, as those no longer maintain orthoscopy over their wider FoV. 
 

Most Plossls, by design, meet the basic lack-of-distortion criteria of orthoscopy. As others may point out, Masuyama’s use of an additional lens element between the two Plossl doublets means it’s not really a true Plossl, but a tweaked one, actually following the design of an old Zeiss recipe, called the “AstroPlanokular”.

 

Reading along in the comments posted prior to this one, I really appreciate the efforts folks use to try to describe the lively & engaging views they enjoy thru these EPs! I find mine produce an inspiring visage!

 

Have any of you tried the 2" 26mm with the 85° fov?

That’s where my Masuyama arsenal tops out at, and I enjoy it very much, as well. It sees less use due to its lower magnification & wider exit.pupil in my f/6 frac… yet in my f/12 Mak, it’s about the first EP I reach for!

Edited by Mike B, 25 March 2025 - 11:21 AM.

[Astrojensen]

My favorite Masuyama? Oh, that's a tough one. I love all of them. I only have the 85° ones - yet - but I love them all. I only got the 32mm and 20mm a few weeks ago, but they became instant favorites.

 

In my first description of them to a friend, who was very curious about them, I described the 32mm as one of the finest eyepieces I've seen, and that the views were amazing, but while the 32mm was superb, the 20mm is pure magic. It's almost impossible to describe. The 20mm is perhaps the highest contrast eyepiece of all time. Certainly the best I've personally seen. And it is comfortable in an almost equally impossible way to describe. You feel like you just want to crawl into the eyepiece and live there. The view feels close, alive and engaging in a way lesser eyepieces can't even begin to touch. 

 

The 26mm, 16mm and 10mm are also amazing. In a recent observation of NGC 4449 with my 6" f/8 Dobsonian, I changed from an 11mm ES82 (in itself a very nice eyepiece) to the 10mm Masuyama 85° and was utterly shocked to find that the view in the 10/85 was brighter than in the 11mm ES82, despite the noticeably higher magnification. I could resolve the core and several knots and HII regions in the galaxy, which came as a complete surprise.

 

My biggest regret is not getting these eyepieces ten years ago. 

 

 

Clear skies!

Thomas, Denmark

[Mike B]

Thomas-

 

Interesting!

 

… but while the 32mm was superb, the 20mm is pure magic. It's almost impossible to describe. The 20mm is perhaps the highest contrast eyepiece of all time. Certainly the best I've personally seen. And it is comfortable in an almost equally impossible way to describe.

Funny, since the 20mm-85* was my first exposure to the line, plus it hit at a fortuitous exit.pupil for both my primary scopes, I’ve since attributed my “favorite” rating on it  due to its being a FIRST… but perhaps there’s more to it?! It may indeed be a uniquely splendid assimilation of optics!

[Far Star]

In post 9 I wrote that the Dioptrx do not fit the Masuyamas. I have to partially correct this statement. The Dioptrx do not fit on the 1.25“ Masus, but they fit perfectly on my 2” 20 mm 85° Masu. I do not need a Dioptrx on this eyepiece, whose eye relief is also too short for use with Dioptrx; but if the ring on the upper side, on which the eyecup is attached, also has the same diameter (approx. 42-43 mm) on the Masus with longer focal lengths, the Dioptrx could be used sensibly with the 32 mm 85° or the 50 mm 53°, for example.

[salishstars]

I just pulled the trigger on the 26mm 85° eyepiece and thinking about getting the 16/85 next. After that, it's a tough choice between the 53° and the 85° for the shorter focal lengths. That 60mm is gorgeous and I fear it has started calling my name, but for the time being,  I am going to concentrate on the shorter focal lengths.

 

Even though I already have the Docter. I am looking at the 12.5mm MOP 53° just because it's so much lighter, smaller,  and easier to balance the scope with. The 10/85 is really attractive too, but I am a little concerned by the fact that some of you seem to like it less due to eye placement/short eye relief. How bad is it? I don't generally have trouble with short eye relief eyepieces so maybe I would be okay with the 10/85?

 

Is there much of a difference in planetary detail between the 85 ° and the 53°? Should I stick to the 53° for the higher magnifications? Are the 53° any better at handling faster focal ratios like from f/8 to f/6 or are both versions best at f/8 to f/10 and slower?

 

Thank you everyone,  you have all been so helpful!

[salishstars]

Just out of curiosity, how do the pseudo-Masuyama eyepieces like the Ultrascopics/Eudiascopics/etc. stack up against the Masuyama 53° eyepieces? I have several of the pseudo-Masuyama eyepieces and with catching the Masuyama bug, I am thinking about replacing them with the 1.25" MOP 53° eyepieces for my 1.25" only scopes.

 

Wow, this hobby gets expensive fast! I am afraid looking through my friend's Masuyama eyepieces really has me hooked. It's hard to explain,  but they were the most transparent eyepieces I have ever looked through.

[Paul Skee]

Being addicted to wide field, I have a number of eyepieces considered to satisfy this urge. Among them are the 3 Masuyama 2" 85 deg. They are excellent in the longer scopes, I accept the aberrations they tend to exhibit in the shorter tubes, the views are worth the compromise. If you really enjoy this type of observing, you might want to try a Brandon 48mm.

[rowdy388]

My only Masuyama is the 32 85. It has become my favorite nebula eyepiece. I read from another member that the rubber eyecup

can be unscrewed making the view even more like a 48 Brandon or 28 RKE with the floating image effect. It works, but the eyelens

is very exposed, and there is a thin metal rim that is painfully cold to touch in the winter.

[CrazyPanda]

Just out of curiosity, how do the pseudo-Masuyama eyepieces like the Ultrascopics/Eudiascopics/etc. stack up against the Masuyama 53° eyepieces? I have several of the pseudo-Masuyama eyepieces and with catching the Masuyama bug, I am thinking about replacing them with the 1.25" MOP 53° eyepieces for my 1.25" only scopes.

 

Wow, this hobby gets expensive fast! I am afraid looking through my friend's Masuyama eyepieces really has me hooked. It's hard to explain,  but they were the most transparent eyepieces I have ever looked through.

I have this same question.

 

I have the 7.5mm, 30mm, and 35mm MOPs. Unlike the 35mm Eudiascopic/Ultrascopic, the 35mm MOP opted to be a 2" eyepiece.

 

However, when I compare the 35mm MOP against the 35 Panoptic and the 34mm Svbony SV136 eyepiece, the sharpness of the MOP is not all that impressive. Stars are tighter and sharper in the 35 Pan and maybe a smidge sharper in the significantly cheaper Svbony (this is at F/6).

 

Daytime testing against a target shows crisper definition and snappier focus in the Pan and somewhat challenging best focus in the MOP.

 

Because of this, I'm hesitant to buy more MOPs, and am curious how these compare to the older pseudo-Masus....

[salishstars]

Have you tried running the same comparisons in a much slower than f/6 instrument? 

[Mike B]

Have you tried running the same comparisons in a much slower than f/6 instrument? 

Most simple EP designs struggle to maintain unaberrated stars pinpoint-sharp to the edges. This includes my 5-element Pseudo-Masuyama Ultima’s, the new 53* MOP I’ve tried thus far, and every 4-el Plossl I’ve ever tried…. And it’s a tougher challenge for them all at f/6! I suspect the only “fix” is to man-handle the converging lightcone with MORE glass members in attendance. OR use a slower primary.

 

i, too, have wondered concerning the fruitfulness of replacing my 52* Ultima’s with newer 53* Masuyama’s. So, using my f/6 frac I recently compared the views with my newer 12.5mm Masu 53* with a vintage 12.5mm Ultima. Both EPs suffered a similar degree of minor outfield lack-of-sharpness, yet seemed identical for the display of stars across the majority of the FoV. What stood out as a difference was not so much the optics, but the ergonomics! The marvelously soft, pliable rubber eyeguard on the new Masuyama was waay out ahead in terms of user comfort- especially for this eyeglass wearer, as it enabled me to grab a quick peek thru the EP while wearing my glasses, during aiming the scope at the sky. Can’t do that so easily with the old Ultima, as the exposed bare metal top is NOT a happy place to hover one’s eyeware lenses in the dark!

 

Having the full spread of vintage Pseudo-M’s…12.5mm, 7.5, & 5mm… and enjoying them all, excellent optical doorways to the heavenly wonders, I’ve still eyed the newer 7.5mm Masuyama for the reasons described above, yet it’s not a FL I’d typically be using for target acquisition, so I think I’m gonna save my nickels & stand Pat with my current EP line-up, new+old.

 

Now, the new 10mm-85* Masuyama, with its ginormous FoV- IS an EP I’ve used for initial-look/target acquisition purposes! For this purpose, that marvelous rubber eyecup is dabomb!

[Matthew Paul]

I thought they all were amazing on axis but should have been made as 68-72deg eyepieces rather than 85, as the outer field is not corrected at all. Even in scopes like a Tak130.

[CrazyPanda]

Have you tried running the same comparisons in a much slower than f/6 instrument? 

No, but all my tests were in the center of the field. I am not expecting critical sharpness beyond the central ~5-8 degrees of the eyepiece. That central region was not as sharp was I would have expected given the pedigree and cost. It's not about element count in this case. My 4 element Tak TPLs are just fine in the center for sharpness even at F/5.3

 

Plus another 5 element eyepiece (the Svbony) was just as sharp if not sharper than the 5 element Masuyama.

 

Maybe even axial sharpness of these eyepieces requires long focal ratios.

Edited by CrazyPanda, 26 March 2025 - 01:11 PM.

[SeattleScott]

Certainly the 85s will struggle more in faster scopes than the 53s. Both are five element designs. The 53s are basically 85s with the field size stopped down to mask off problems in the outer field in fast scopes.

I don’t have the new MOPs, but the pseudo Masuyamas that share similar/same optical design, have roughly similar correction as a Plossl. I think one would be perfectly happy with them at F6 or higher. F4 did show significant abberations in the outer field.

Edited by SeattleScott, 26 March 2025 - 01:39 PM.

[Mike B]

Certainly the 85s will struggle more in faster scopes than the 53s. Both are five element designs. The 53s are basically 85s with the field size stopped down to mask off problems in the outer field in fast scopes.

I don’t have the new MOPs, but the pseudo Masuyamas that share similar/same optical design, have roughly similar correction as a Plossl. I think one would be perfectly happy with them at F6 or higher. F4 did show significant abberations in the outer field.

Didn’t Al Nagler’s re-cooking of the std. Plossl recipe retool the TV models for improved serviceability down to f/4? Or was his re-cooking not specifically FL-dependent?
 
ive lonnng enjoyed the highly-corrected widefield views of monster glass-stack eyepieces! Such a viewing attribute is truly a market THING, and carries with it a unique outlook on optical correction & the suppression of aberrations.
 
And yet- more recently I’ve followed to some degree the minimal-glass approach, also a market THING, and have been struck by the superb contrast & amazing transparency of the views rendered- despite the less-than-ideal edge correction that seems to attend at f/6. And when others describe a “lively” character to their views, it resonates… stellar colors are notably vivid, and faint nebulosity pops out more readily. As a result, my own outlook on outfield correction and outfield aberration tolerance has modified, due to what is displayed on-axis & over the majority of the FoV!
 

I thought they all were amazing on axis but should have been made as 68-72deg eyepieces rather than 85, as the outer field is not corrected at all. Even in scopes like a Tak130.

Masuyama DID, in the past, release some EPs having their optical secret sauce, yet stopped back to a 65* AFoV. When the FR of so many of the Japanese scopes is considered, f/9 & longer, Masuyama’s 85’s are suited quite nicely. It’s only the relatively new market phenomenon of hyper-fast FR’s for which their 85’s are lacking in outfield aberration suppression. 
 

In view of this, I wonder where the general Japanese scoping market & mindset are TODAY re: the hyper-fast FR phenom?