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What's the deal with Miyauchi?

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#1 btschumy

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Posted 25 July 2004 - 03:02 PM

I'm curious as to what's the deal with Miyauchi. On paper their binoculars look great. However, I've seen review after review of them that describe problems. These include:

1. poor collimation
2. soft focus
3. excess color (even in flourite version)
4. individual focusing eyepieces too loose
5. IPD adjustment too tight

I have also seen a couple of people that rave about theirs. I can only assume there is very poor quality control on them.

Several years ago I purchased a pair of the 20x77 "Exceed" Miyauchis from Texas Nautical. I personally had problems 1,3 and 4. I sent them back to TN for collimation and they still came back with problems.

The reason I ask is that I am still in the market for a quality 90 - 100 mm binocular. I recently got the Oberwerk 20x90s, but I'm just not sure I'm happy with them. They are OK, but not exceptional. I'm really spoiled by some nice refractors I've had and I want similar performance in a large binocular. The Miyauchi 20x100s look promising but that quality control problem really bugs me. I don't want to go through several pair to get some I like.

Anyone know of anything else I should be looking at? I'm probably willing to spend $2000-$3000 for something that is really excellent. I've even thought about the Nikon 20x120s and the Fugi 25x150s but the 6mm exit pupil would probably mean I'm throwing away 20% of the aperture.

Thanks for any thoughts.

Bill

#2 KennyJ

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Posted 25 July 2004 - 03:16 PM

Bill,

If you go to "search" at the top of the page and type in the words " Kowa Highlander" over a 2 year period , you will find a thread of posts that touches on the availability on one or two "high -end alternatives" to the Miyauchis.

The comments and links might be of some interest to you.

Regards , Kenny.

#3 lighttrap

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Posted 25 July 2004 - 04:40 PM

My sample size is small. But, I've been fortunate enough to have several hours each with Miyauchi 20x77 BS ibs, 22x71 NBA Saturns, and 20x100 Bj-ibs. Of these, the only one that I'd recomend is the x71 NBA Saturns. And keep in mind that it took (2) samples for me to even feel comfortable recomending those. To put it bluntly, either Miyauchi has QC problems AND/OR some of the US distributors may or may not know what they're doing when it comes to collimating these binoculars. It's very interesting to me that when one goes to the trouble to track down the rave reviews of Miyauchis, they tend to have come from purchasers who purchased them from Texas Nautical. This is NOT a slight or a slam against anybody, or any corporation. Nor is it an endorsement. It's simply what one guy has learned when looking into the matter of the apparent vehemently different perceptions of various Miyauchi owners as represented in the US. I've always felt like Miyauchi binoculars ought to offer lots more potential than what they usually deliver. Bear in mind, that statement is not at all intented to inflame the various well satisfied Miyauchi owners out there. Not at all. It's just that amongst the small sample of Miyauchi binoculars that I've personally seen, (5 total), I think this brand suffers from more QC issues than one should have to put up with in this price range. That's all. This is just one guy's opinion. Nothing more.

Peace,
Mike Swaim

#4 edwincjones

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Posted 26 July 2004 - 05:12 AM

I had a brother in law with a jag--he loved the fine tuned
car but it was in the shop every other week. My Miyauchi

#5 edwincjones

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Posted 26 July 2004 - 05:27 AM

Sorry-hit the button too soon. My miyauchi 20x100 Fl has
4/5 flaws (collination is good) but remains my favorite
binocular due to sharpness of image, contrast, protability
and style (yes this does count). I also have the fuji
25 x 150 which is better build, better light gathering,
but optics not quite as good and much less portable.
I have never seen a Kawa but have heard the raves- you should check them out.
My main complaint with the nameless dealer (who owns this
site) was the miyauchi's came in a double box without padding or instructions. Mike did try to get them without success from Texas Nat.
Ed Jones

#6 btschumy

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Posted 26 July 2004 - 08:30 AM

Bill,

If you go to "search" at the top of the page and type in the words " Kowa Highlander" over a 2 year period , you will find a thread of posts that touches on the availability on one or two "high -end alternatives" to the Miyauchis.

The comments and links might be of some interest to you.

Regards , Kenny.


I looked through the threads here and on the Astromart forums on the Kowas. They do sound nice although I always take Markus Ludes's opinions with a grain of salt.

The price is definitely "up there", especially when you add in the alternate eyepieces ($900 a pair!). I was not able to find any information on the interpupillary distance. I need it to go down to 58.

My other concern, and this might be a deal breaker even if the price was not, is that the eyerelief is a bit tight. I wear glasses and the eyerelief is 16.5 and 17 mm with the 32x and 20x eyepieces respectively. My Nikon SEs have 17.8 and thatis about as tight as I can go and see the full field stop. I would have to actually try a pair to see if they worked. Different manufacturers seem to measure eyerelief slightly differently.

#7 BarrySimon615

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Posted 26 July 2004 - 09:28 AM

Negative reviews kind of had me apprehensive too for awhile. When a pair of 20x77 Miyauchi became available about 4 years ago used from someone I know and trust (Tony Miller) I bought them. Additionally reviews also indicated that these had less color error than their 100 mm big brothers, they could work well with a tripod I had and the cost was not beyond my means. I have not regretted buying them.

I will agree with the fact that the eyepiece focus was too loose, not loose in the sense that it was woobly, but just too smooth and hair trigger. A doodle bug harnessed to the eyepiece barrel could probably turn it. Additionally while the focus was good and the stars were sharp, the left barrel was slightly sharper than the right. This is unfortunate as my right eye is the dominant one. I would have preferred the better barrel to be the one on the right.

Just about a year ago I decided to get the 20x100 Miyauchi too, the non-fluorite model, as the price difference was just too great to justify the difference. I was concerned that all the reviews raved about the fluorite and said they were really worth it compared to the non-fluorite, however my experience with apo and non-apo refractors at these powers told me that I did not need fluorite. My Miyauchi 20x100 came from Oberwerk - Big/Binoculars. Kevin's price was so much better than his competitors that it seemed like he was almost giving them away. I had had a previous opportunity to test the Burgess clone of the Miyauchi and was smitten by the overall styling of the binoculars. Unfortunately the Burgess clones were not well collimated, had undersize prisms and were not fully coated or multi-coated (all problems subsequently rectified, I am told, in later versions).

When my 20x100's came in they looked fine (they are not particulary well packed from the factory). Kevin does bundle them up well in bubble paper, and mine came in good shape and without damage. They turned out to be well collimated, and the focusing action was tighter and more to my liking. My particular pair is sharp to virtually the field edge and I find no disparity in sharpness comparing the left barrel to the right. I am very happy with them.

They have been compared to the fluorite version and I will say that if you will be studying Venus, Jupiter and Mars extensively at 20 to 37x you may want the fluorite version. However if you will be looking at clusters, galaxies and nebula, use the money you save by buying the non-fluorite version to get the 26x and 37x eyepieces pairs to make this instrument more versatile. I am very, very happy with mine.

One word on collimation, I would suggest that any purchaser have the seller ship the binoculars in an appropriate case to minimize any chance of collimation shift in transit. (I have mine in a Pelican 1550). Find out what the policy is on collimation and how they collimate. (One seller of Miyauchi collimates binoculars by using a distant tv station transmission tower as a target and does this from inside the store going thru a thick plate glass window at about a 45 degree angle. Maybe this is ok, but no collimator is used. It is just a human eye collimation and I would think that the plate glass window, with it's imperfections has an effect. Comments about this?)

I too have read some glowing reports about the Kowa binoculars including Phil Harrington's review in ASTRONOMY magazine. They cost about 4 times the price of the 20x77 Miyauchi for just a few millimeters more aperture. They would have received strong consideration from me had they been half their price, but $4000 for about 80 mm aperture is way out of my league.

Barry Simon

#8 btschumy

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Posted 26 July 2004 - 09:52 AM

Negative reviews kind of had me apprehensive too for awhile. When a pair of 20x77 Miyauchi became available about 4 years ago used from someone I know and trust (Tony Miller) I bought them. Additionally reviews also indicated that these had less color error than their 100 mm big brothers, they could work well with a tripod I had and the cost was not beyond my means. I have not regretted buying them.

Barry Simon


There's currently a pair of the Miyauchi 20x100 semi-apos on Astromart that just slipped of the the "current" ads (Classified #285334). He wants $1400 for them. I might email him and see what his experience has been with them.

#9 Guest_**DONOTDELETE**_*

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Posted 26 July 2004 - 07:25 PM

Bill,

The Kowa HighLander interpupillary minimum distance (as close as I can measure it) is 55 or 56mm. I'm not sure how to accurately measure eyerelief, I'm afraid.

I find the pair I own to be mechanically, and optically, perfect in every way.

Good luck.

#10 Guest_**DONOTDELETE**_*

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Posted 27 July 2004 - 09:50 AM

I have an older version of Miyauchi 20x77 that I purchased directly from a seller in Japan several years ago. This is a version without the interchangeable eyepieces. Mechanically it is excellent with none of the looseness or tightness. The helical eyepiece focusing is smooth without without a hint of looseness. When you set to focus, it stays put. Same goes for the IPD adjustment.

Optically, it is also excellent given the design limitation. In my version the sharpness at the center is quite good, however, aberrations begin to dominate towards the edge. Overall, the view is very pleasing. Because of its long eye relief, the view is somewhat sensitive to your eye position, especially for daytime views. You will objects surrounded by blue/purple fringing unless your eyes are well aligned with the exit pupil. Overall, I would say that the color correction in my Miyauchi is better than most 20x80s.

The focus is sharp, allowing me to routinely resolve three stars in Trapezium. Of course, the collimation is excellent, which is not an easy thing to achieve in this type of complex optical design.

Once I made an extensive study of Vixen BT-80, a design similar to Miyauchi 20x77. My conclusion was that due to the way BT-80 achieves binocular collimation, you will no doubt see flares in the image. The amount of flaring you get depended on how much the prism seats had to be moved to achieve binocular collimation. This partially explains spotty performance record of Vixen giant binoculars. It may be that Miyauchi uses the similar mechanical setup and afflicted with same problems.

Finally, some thoughts about Miyauchi 20x100s. The 45 deg. version uses a roof prism to achieve correct image. I think many reports of so-so performance of 20x100 may have something to do with the quality of this prism. By design the roof prism is inferior to porro prisms unless the roof prism is extremely well made and has phase correction coatings. That's why the high end Zeiss, Leica, Swarovski, Nikon etc. roof prism bincoulars are so expensive.

Given the price of 20x100, I am quite certain that the roof prisms Miyauchi use probably are not in the same quality category. There are ways to avoid much of this problem my using only partial aperture of the roof prism. I am not sure whether Miyuachi 20x100 uses this method. Anyway, I have a feeling that 90 deg version of the 20x100 may be a better performer as it uses porro prism instead of roof prisms.

Mike

#11 sftonkin

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Posted 27 July 2004 - 10:10 AM

Mike wrote:
>Finally, some thoughts about Miyauchi 20x100s. The 45 deg. version
>uses a roof prism to achieve correct image. I think many reports of so-so
>performance of 20x100 may have something to do with the quality of this
>prism. By design the roof prism is inferior to porro prisms unless the roof
>prism is extremely well made and has phase correction coatings.

As a pointy of information (which you may already know) the roof prism in the Miyauchi 20×100 is a 45º Schmidt (I think) roof, not the Pechan roof that one usually associates with binocs. There are fewer interactions of loght with optical surfaces in the Schmidt, and none needs to be reflective (as in silvered) as all reflections are by TIR.

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Posted 27 July 2004 - 11:06 AM

Stephan,

You are correct that the roof prism in Miyauchi is a Schmidt prism. However, most handheld roof prism binoculars also use the same Schmidt prism paired with a 45 deg deviation prism. The combination of 45 deg deviation prism and the 45 deg schmidt prism is what you are referring as a Pechan roof prism. The problem with a roof face is that it splits the light cone and recombines it, and some light recombines destructively to lower contrast. One can expose the light cone to one side of the roof at a time to avoid the destructive interference problem. I believe the Russian boarder binoculars (Sovietski 15x110) use this type of scheme.

Mike

#13 lighttrap

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Posted 27 July 2004 - 11:11 AM

Once I made an extensive study of Vixen BT-80, a design similar to Miyauchi 20x77. My conclusion was that due to the way BT-80 achieves binocular collimation, you will no doubt see flares in the image. The amount of flaring you get depended on how much the prism seats had to be moved to achieve binocular collimation. This partially explains spotty performance record of Vixen giant binoculars. It may be that Miyauchi uses the similar mechanical setup and afflicted with same problems.


This is interesting. As is the info that Miyauchi uses Schmidt roof prisms in their 100mm. I actually purchased a used set of BT80s after doing a direct comparison of them to the Miyauchi 100mms. That orig. test was posted to this board, earlier this year. Amongst the 2 samples I looked through, 2 of us, fairly experienced optical equipment junkies both thought the BT80s had lots better contrast, sharper images and less CA and less flaring. However, I'd not be at all surprised if different samples would've yielded different results. As I understand it, the BT80s are more subject to going out of collimation easier. Still, I feel that part of the problem with the Miyauchi 100mms that we tested was that they were likely not properly collimated to infinity. It'd be interesting to see a whole selection of both models that were in perfect collimation by one of the experts like Bill Cook or Cory Sudarth. I think there would likely still be some variation amongst samples.

#14 777Guy

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Posted 28 July 2004 - 05:39 PM

I recently purchased a Miyauchi 20x77 BS77i. I bought them through Anacortes Telescope and they come via Texas Nautical. It is my understanding that Texas Nautical resets the focus to infinity and checks for optical errors before shipping. So far, I am very pleased with my pair. I use them for both terrestrial and celestial viewing. My subjective impression is that resolution and contrast are very good and color abberation is undetectable, even looking at bright objects such as the Moon. I particularly enjoy the comfort in viewing near the zenith with the 45* eyepieces. However, as good as the 77mm model is my impression of the 100mm non-flourite is just the opposite. I was able to check a pair out about a year ago and was amazed at how much CA was present and how dim the image was.
I have experienced none of the problems mentioned. The collimation is right on, the focus is smooth but is very sensitive and precise. The IPD adjustment works just fine and can accept very narrow IPDs. My only complaint is the the eye cups are too hard and not adjustable.
I haven't had a chance to really review them for their stargazing quality but the other night I was outside with them and was just panning for fun and saw several star clusters, double stars and other faint DSOs. I also had really nice views of Comet NEAT and LINEAR last month when they were visible. I would recommend them to anyone who is looking for high quality binos at a resonable price.


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