Masuyama 32mm 85* Degree

[FlashDrive]

Masuyama 2" inch 32mm 85*degree .... Outstanding fov and the views are spectacular using my TAK f/8.

When wifey took a look .... her immediate response was OMG ' your not getting rid of this one ' .... don't you dare :mad:

We were looking at ' Star and Globular Clusters ' most of the evening :astron:

I had to admit this is an outstanding Eyepiece and well worth the money.

Col....

[MortonH]

Wouldn't mind one of these myself!

[FlashDrive]

Aussie $$ is looking better now ... you'd get it at a better price than I paid.

Col....

[LewisM]

Japanese illusions - see, they silk screen printed the stars on, Col!:rofl::P:D

[Hoges]

How's the eye relief on these for glasses wearers?

[FlashDrive]

20mm Eye Relief .....

http://agenaastro.com/masuyama-2-inch-eypiece-32mm-mop-32.html

[FlashDrive]

:confuse3: ..... what rubbish :screwy:

:D

[AstralTraveller]

It's amazing they can get such quality in an 85* afov with only 5 elements. The original 5 element 'super-plossls' had a 55* afov. The wonders of modern glass??

[croweater]

I had a Parks Gold Series 10mm which I think is a Masuyama copy. Really nice eyepiece but I think it was 52* FOV. Cheers Richard

[Wilso]

Hi Col,
Congrats nice looking eyepiece, I had been looking at the masuyama as well but ended up ordering the nagler 31. It would be good to compare the two if you've tried them both.

[LewisM]

I bought a 10mm Parks Gold recently and it is simply superb, especially in the A-P Star 12ED. I paid peanuts for it.

Not only are they a Masuyama "clone" but apparently so are the Tak LE's. There is even conjecture that Masuyama MAKES the Tak LE's and made the Parks Gold series EP's. Interesting if they did!

A friend has the exact same Masuyama Col shows - will bug him to let me try it.

[FlashDrive]

Yes...that would be a good ' shoot out ' to compare each other.

The Aussie $ is now pushing the 80c mark ... very tempted to obtain the Masuyama 26mm 85* degree also.

Col

[FlashDrive]

I'd do that Lewis ... it's an extraordinary piece of ' glass '

Col....

[Boozlefoot]

Have been wanting one to complete my EP collection, and now sweating on my tax return to come through! (Isn't this what tax returns are for?)

[ausastronomer]

Hi Lewis,

The same eyepieces were sold as:-

Parks Gold Series
Antares Elite
Celestron Ultima
Orion Ultrascopic

They were essentially identical except for some slightly different coating specs. They all seemed to perform the same to me in the field. Optically they are excellent performers, outside of the 50~ degree fov and tighter eye relief in the shorter focal lengths. I like them a lot, really nice sharp contrasty images.

Meade also did a 5 element Series 4000 super plossl for a few years which was very similar and performed at the same level.

The Tak LE's use a similar optical design with a different housing. I am fairly sure they have fractionally longer eye relief (by about 1mm) for a given focal length than the others.

Cheers
John B

[ausastronomer]

Hi Col

Have you tried it in the Portaball?

I am curious to see how it goes in scopes faster than F8. I think as David mentioned, it might struggle at faster than F6 due to only 5 elements and 85 degrees.

In those slower scopes I am sure it will perform really well with sharp contrasty images.

Cheers
John B

[electric]

The Masuyama line was designed for refractors - that is where the Japanese market is concentrated on.

If you use the Masuyama eyepieces on Newtonians, you will find few perform well edge to edge. Pop them into a refractor, as Col did, and here they excel.

Same for the other Masuyama copies. Great in refractors, and mediocre in Newtonians.

"Fast" vs "Slow" focal ratio has nothing to do with it. What has everything to do with it is matching the shape of the focal plane of the scope with the eyepiece you are using. No use putting an eyepiece designed to work with a convex focal plane in a scope with a concave focal plane.

With the complex nature of contemporary eyepiece design, there will be a couple of the Masuyma line that will perform well in a Newtonian. But that does not mean that the others are crap. They are not. What is crap is expecting an eyepiece designed for a refractor to perform the same in a Newtonian.

Col's experience of this monster new Masuyama is in a refractor, and it performs as expected - brilliantly. Will it perform just as well in a Newtonian - who cares! It may or may not. A Newtonian is not the right scope for this eyepiece. A refractor is.

Electric.

[FlashDrive]

John ..... my PortaBall only takes 1.25 Eyepieces and is of a ' Helical ' Design.

Superb in ' Fluorite ' TAK f/8.... I haven't got around to using it in my f/15 Refractor .

Excellent in ' slow ' f Ratio instruments.... more so Refractors

Cheers Col....

[AstralTraveller]

A good point, though I can't imagine that the f-ratio counts for nothing. For one thing, it will affect the radius of curvature of the focal plain. I also note that people who appear to know far more than I (which is little enough) do specify a minimum usable f-ratio for different eyepieces.

So how do SCTs, Mak, and RCs fit into this picture? Are they curved similar to newts of fracs?

[FlashDrive]

Just a Pic .... so it did happen .... ;)

Col...

[electric]

Of course the focal ratio counts for something. As you say, it affects the radius of curvature of the focal plane along with the focal length of the telescope. This is most significant with photographic applications. One example being the requirement of scope specific field flattner and focal reducers. If your scope is an ED80 f/7.5 refractor, you need flattner specific for that scope - you cannot use one made for a 100mm f/9 refractor. Astrophotographers are most aware of this.

As for catadioptric cassegrains, these produce a convex focal plane due to the, shall we say "hyperbolic" or negative secondary mirror. It is the shape of the secondary mirror that increases the native focal length of the primary to what the telescope is specified as being, and changes the shape of the focal plane. Despite the concave primary mirror.

This can be seen with the way the convex specific eyepieces also perform well in catadioptric cassegrains. Also those cheap and nasty 0.5X focal reducers, these work ok as general purpose focal reducers in refractors and catadioptric scopes, but not Newtonians. Even in slow Newtonians these reducers do not perform as well as with Cats.

Field curvature also be seen in convex specific eyepieces when used in fast refactors. These eyepieces are also cheaper. Even the older Masuyama eyepieces, SOME individual focal lengths can exhibit a little field curvature in very fast refractor. Remember, the original Masuyama eyepieces were designed when refractors were typcially slower than what is available today. Yet the degree of field curvature is nowhere as significant as in a Newtonian. Again, this is not a flaw in the eyepiece, but a factor of the design parameters of the time thirty years ago. Whether these new Masuyama eyepieces are designed for slower refractors as its predecessors or the more contemporary faster refractors, we have to see. I would suspect as yes to faster refractors due to the very large apparent field of view that they offer. But to dump all telescope designs as being the same with regards to shape of focal plane and only making the distinction as "faster" and "slower", that's disingenuous.

It comes to understanding the pedigree of the eyepieces you are using and coupling them to the most appropriate instrument. Unfortunately this is the hard part, and many reviews are written by people who do not understand this enough or have a vested interest.

Anyone have an f/5 APO to try out one of these? Oh, and most fast APOs come with built in field flattners, making things even more complicated, like the Skywatcher Esprit line.

Collin, did your refractor have a field flattner in it when you used the Masuyama?

[FlashDrive]

@electric .... no, not at all .... stock standard TAK78 f/8

Col...:)

[casstony]

I expect edge performance of the Masuyama to be similar to that of other wide angle 5 element eyepieces (ie. challenged in many types of telescope). Televue and Explore Scientific don't use a bunch of lenses to correct aberrations just for the fun of it.

It might be good in the Celestron Edge scopes with their flat fields and slow f/ratio, as well as slow refractors.

Note to Electric: most fast APO's don't come with built in flatteners, they're usually an add on device for imaging (including the Esprits which are triplets with an accessory flattener). There have been a few designs released more recently which do include flatteners built into the design, in addition to the long standing FSQ and NP.

[Wavytone]

Tony is correct.

In short there is no such thing as the perfect eyepiece for all telescopes.

Unfortunately eyepiece manufacturers do not state what the field curvature is, which is unfortunate as a lot of observers waste money on eyepieces that aren't a particularly good match for their scope. Morton you're reading this far, right ?

The issue is that the curvature of the focal plane can be convex or concave towards the objective (and sky). For refractors, SCTs, maks and cassegrains it is concave towards the sky. For Newtonians however the focal plane is CONVEX.

The reason this matters is that the curvature inherent in the Masuyama (and for that matter a nice 38mm ProStar eyepiece I have) is that the curvature in the focal plane of the eyepiece is a fair match for that in small refractors and cassegrains.

Much like stacking two soup bowls on top of each other, a close fit.

But in a Newtonian the curvature is opposite to that of the eyepiece and the result is like stacking soup bowls back-to-back - they touch at one circle (in focus) but for the most part are far apart (out of focus). In a scope, you can't get the whole field to focus and have to rack the eyepiece in and out only to find there is no sweet spot where most of all of it is in focus.

While at f10 or even f13 it might not seem much of an issue, it is noticeable in sharp optics at f7. At f5 it is irritating to the extent you'll be looking for something that is a better match. And while field flatteners may help they don't really fix this especially for fast Newtonians.

Conversely the humble Plossl has field curvature that is a great match for Newtonians, but not refractors.

Televevues main market is the US where big dobsonians rule. So it is no surprise their eyepieces are a good match for these. But in Japan and Europe smaller refractors are the biggest seller and hence their eyepieces are intended primarily for these.

[bytor666]

Apparently not good in fast scopes...

[Tropo-Bob]

Well, I am humbled. I have not heard this concept before, which is remarkable since I have been in the hobby for over 50 years. It shows that one continues to learn something every day!

I assume from the above quote that orthos are a better fit for refractors than reflectors? (It certainly seems valid from my experiences).

[Wilso]

If anyone's interested there is a review/article on CN about the 26mm masuyama eyepiece as well.
Cheers

[LewisM]

I LOVE my Masu 25mm (the original short version).

I have owned and tried a LOT of TV's, and have yet to find one I like. Just not MY flavour.

[Don Pensack]

Reviews of 3 different Masuyamas:
https://www.cloudynights.com/articles/cat/user-reviews/comparing-the-masuyama-25mm-52°-25mm-65°-and-26mm-85°-r3122

[Don Pensack]

Righto.
Also:
Tuthill Plössls
Omcon Ultima
Astroplan "Super Plössls"
All were made in Japan.
The Meade 5-element Series 4000 "Super Pössl" was made by Kowa in Japan.
Of them all, the only one still in production is the Takahashi LE.

[Tropo-Bob]

I have some LEs, but much prefer the Tak Orthos. Then again, I mainly use refractors so maybe its horses for courses ...

[Wilso]

Hi Col,
If you still have the masuyama 32? and do you happen to know the field stop size for this eyepiece, just trying to compare it to my 31nagler grenade.
For that matter and a few of the others in the range as well.
Masuyama 45mm , 26 and the new 16 baby (anyone?)
The 45mm has the original 53deg afov! but no one on line seems to list the field stops.

Thanks

[FlashDrive]

Here you go .....

Col....

[Don Pensack]

You can find that information and more about over 1000 eyepieces here:
https://www.cloudynights.com/topic/612955-2018-eyepiece-buyers-guide/

[Wilso]

Thanks for that guy's.

Interesting stats between 31nagler and the 32 Masuyama, not much between the two besides weight and the Masuyama has the largest field stop available in a two inch eyepiece !
Over 500g of weight saving and and an extra .3 tfov in my f8

[foc]

I have a Matsuyama 32mm 85. I do not think it is nearly as well corrected in the outer 30% compared to a teleview nagler. But it has very good light transmission and it is light and I do not like very heavy eyepieces. It would be well suited for large globular clusters or the Eta Carinae region. It is also a nice low power finder eyepeice if I do not have a finder fitted.

Oddly enough, when using it for looking at star fields, I prefer the view in my GSO 10 inch Dob than my 140mm f7.5 refractor but that might well be because of the effect of the secondary or because my Dob does not have any correction for coma and my expectations are lower. I also enjoy it in my 102mm f8.6 refractor which is a bit more light starved than the 140mm and perhaps benefits from the slower f ratio.