62 replies to this topic

[ewave]

I have only one Masuyama, the 50mm/53 degree. So by default it is my favorite Masuyama. BUT it is also one on my favorite long focal length eyepieces of my whole collection.

In my C11 Edge operating at F/7, the Masuymama provides excellent max exit pupil views with crisp stars to the edge. It gives me the best Rosette Nebula view of all my long FL eyepieces (Pentax 40XW, ES40-68, ES30-82, ES25-100, AT20-100XWA).

I have the 16/85 on my wish list for planetary binoviewing at F/17-F/26.

I was thinking about putting the 50mm Masuyama on my list, especially for my C9.25 edge.  I assume you are using the dedicated reducer for that, that must be a heavy setup for visual. How is the correction of the 50mm in your C11 Edge without the reducer?  

[ABQJeff]

I was thinking about putting the 50mm Masuyama on my list, especially for my C9.25 edge. I assume you are using the dedicated reducer for that, that must be a heavy setup for visual. How is the correction of the 50mm in your C11 Edge without the reducer?

Yes I am using the dedicated reducer. Not too bad on weight: 2” diagonal, filter wheel, reducer and 80mm finder + RDF on dual finder bracket weighs total of 7 lbs. So 35lbs with scope. My mount has a 45 lb limit on each arm, so not a problem.

I don’t use my 2” eyepieces in my C11Edge without the reducer, so I wouldn’t know on correction in F/10 mode. Can’t see it getting worse.

[MichalKaczan]

I use Masuyama 20mm/85* in f5 60mm, 150mm binoscopes and Newton 22" f4. For me, the contrast, sharpness in the central parts of the field of view and transmission are unrivaled. Binocular viewing means that, despite F5 , the image looks much better than in mono, and the field of view is amazing. I don't know if the brain "compensates" for marginal defects. Masuyama works great with the APM 1.5x telecentric barlow, in which the edge defects in the f4 telescope are very small. 

[saemark30]

I think the original  legendary Masuyama eyepieces are the most attractive.

It would be informative to compare them to the current MOP series.

Edited by saemark30, 30 March 2025 - 01:18 PM.

[helpwanted]

Are there any design differences between the 85° and 53° versions, other than the fov? 

[Mike B]

Are there any design differences between the 85° and 53° versions, other than the fov? 

I’ve been wondering that for quite a while! Both 5-el…. Beyond that, I do NOT know…. Is it just a different dia. Fieldstop? Hmmm…

[balcon3]

I’ve been wondering that for quite a while! Both 5-el…. Beyond that, I do NOT know…. Is it just a different dia. Fieldstop? Hmmm…

It doesn't see that the 53's are just 85's with a smaller field stop, if that is what you are asking. The 85's are fatter above the field stop, so I imagine that there is a design difference in order to get the wider field to converge in the 85's. 

Edited by balcon3, 30 March 2025 - 01:42 PM.

[Sarkikos]

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

Not bad at f/12 either.  That will produce a 5mm exit pupil.

 

Mike

[Sarkikos]

I have these 85-degree Masuyama's:  10, 16, 20, 26, 32mm.  I also have a 60mm 46-degree.  I use them in my slower scopes.  

 

My favorites are the 32 and 60.  If I had to choose one of these two, it would be the 60mm.  It gives me a nice 5mm exit pupil at f/12.

 

My least favorite is the 10mm because of the short eye relief.  

 

Mike

Edited by Sarkikos, 31 March 2025 - 04:38 PM.

[Highburymark]

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

How do they compare on axis with the Zeiss OPMIs, Thomas, if that’s a comparison it is possible to make? I guess you can only consider the 26mm as comparable.

[TayM57]

First is designing a telescope that is optimized to provide the maximum contrast and resolution of a view of the moon...in particular the whole moon at once. A nearly color free well baffled refactor with good glass and impeccable polish is probably the main contender.
 

Not to be rude, but who looks at the moon with the entire disc in the FOV? That gets boring pretty quick. I spend my time on Luna in the 180-500x range.

 

Edit: I forgot that the refractor people like to do that. Disregard my question.

Edited by TayM57, 31 March 2025 - 11:57 PM.

[Astrojensen]

How do they compare on axis with the Zeiss OPMIs, Thomas, if that’s a comparison it is possible to make? I guess you can only consider the 26mm as comparable.

I've not done a direct comparison, but nothing I've seen indicates that the Masuyamas aren't at least as sharp, though they are perhaps more sensitive to accurate on-axis eye placement. 

 

I'll do a comparison, when I get the chance. If I remember it... Ideally, it should be done with a very long focal ratio refractor, to eliminate as many other variables as possible. 

 

BTW, I also have 20mm OPMIs, so I can also compare with the 20mm Masuyama - which is going to be a tough fight, because the 20mm Masuyama is sharp.

 

 

Clear skies!

Thomas, Denmark

Edited by Astrojensen, 01 April 2025 - 12:48 AM.

[39.1N84.5W]

I'm still looking for observation reports on the 20mm 1.25" Masuyama vs Baader 18mm orthoscopic. guess I'll have to buy a Masuyama and find out.