Nikon WX 10x50 (1 Viewer)

[Holger Merlitz]

Here is a strange event. Three days ago I was at a photo place in Lausanne called PhotoVision (packed with great stuff), they had a Sony demo that day that I was curious to check out. So this part went fine and then I noticed on the floor those Nikons WX 10x50 (with the Nikon anniversary label). I took a closer look and first thing I noticed was a thin layer of dust(!) on them, so I wiped it off and asked an assistant if I could look through them. He was happy to oblige, took the bins off the tripod and gave them to me. First impression: despite the warnings, they didn't seem too heavy (but then I have years of Fujinon TechnoStabi in my arms ). But the most important was the second impression when I looked through them. I'll set it in a separate paragraph:

The impression was very firmly underwhelming. I was shocked!! My Nikons 8x30 EII look like much better, it's like I'm standing next to an IMAX screen. OTOH the WX looked just like any other binocular with an average field of view except its exit pupil and eye relief were both top notch.

So was I doing something wrong? Is there some setting in the ocular that ought to be taken care of first? The image was very sharp and bright otherwise.

You would have to twist down the eyecups to see the full field, I usually keep them one notch above their lowest position. Apart from that, the 8x30 EII is definitely a very nice and immersive binocular!

Cheers,
Holger

 

[JanPB]

No! Haha, I went back home, looked through my EII and was duly blown away again! Is there a difference in the AFOV between the 10x and the 8x WX? I'll go to that shop again soon (a handy-dandy dusting cloth in hand) and try it one more time. I noticed the oculars had twistable rings around them, do they have to be set up or pulled out/in correctly first? Those rings are different than the focus adjustment which consists of simply turning the entire ocular. BTW, would it kill Nikon to add, at this price, a focus adjustment that works on both oculars at once?

BTW, are the optical data for that binocular available anywhere? I mean full details of the optics, like in a patent application or something?

BTW-squared, I had no idea you wrote a serious book about binoculars! Looks very tempting.

 

[JanPB]

You would have to twist down the eyecups to see the full field, I usually keep them one notch above their lowest position. Apart from that, the 8x30 EII is definitely a very nice and immersive binocular!

Cheers,
Holger

Ah, that probably explains it, as the eyecups were all the way out. In that case, what is their function then? Other than making the user confused that is.

 

[Holger Merlitz]

No! Haha, I went back home, looked through my EII and was duly blown away again! Is there a difference in the AFOV between the 10x and the 8x WX? I'll go to that shop again soon (a handy-dandy dusting cloth in hand) and try it one more time. I noticed the oculars had twistable rings around them, do they have to be set up or pulled out/in correctly first? Those rings are different than the focus adjustment which consists of simply turning the entire ocular. BTW, would it kill Nikon to add, at this price, a focus adjustment that works on both oculars at once?

BTW, are the optical data for that binocular available anywhere? I mean full details of the optics, like in a patent application or something?

BTW-squared, I had no idea you wrote a serious book about binoculars! Looks very tempting.

Yes, the patent application contains lots of details. Thanks a lot, you should have a look into my book

Cheers,
Holger

 

[Tringa45]

You may have to pay 20% VAT and customs duty if declaring and have the binocular confiscated if going through the green channel.

And all that having paid excess baggage!

 

[Patudo]

OTOH the WX looked just like any other binocular with an average field of view except its exit pupil and eye relief were both top notch.

I can see how someone might think that. The WX's big party trick is that it gives you a really wide field of view, at 10x magnification, that is sharp and well corrected across that entire field of view. It isn't as stunningly bright as a HT (its coatings must be excellent, but the sheer number of air to glass surfaces chips away at total light transmission), colour rendition is neutral and pleasant but doesn't suffuse you in Leica saturation, its central sharpness is excellent but can be matched by other alpha class binocular. If you aren't impressed by wide field of view, and don't bother to look at the edges (as lots of commentators here claim to do/be), and don't have an appreciation of the difficulty and complexity of designing and manufacturing an optical train with those specifications, the WX may not seem that special.

 

[wllmspd]

I had a look though the 10x WX, I found that I couldn’t see the full field, I could purposely look round the corner to see the field stop. I’ve had a similar issue with 82degree Nagler eyepieces in my binoscope. I now use 76degree eyepieces that provide good eye relief and a big field I can take in fully. Be good for the NL/SF/BannerCloud to give us a few more degrees AFOV….

Peter

 

[JanPB]

I can see how someone might think that. The WX's big party trick is that it gives you a really wide field of view, at 10x magnification, that is sharp and well corrected across that entire field of view. It isn't as stunningly bright as a HT (its coatings must be excellent, but the sheer number of air to glass surfaces chips away at total light transmission), colour rendition is neutral and pleasant but doesn't suffuse you in Leica saturation, its central sharpness is excellent but can be matched by other alpha class binocular. If you aren't impressed by wide field of view, and don't bother to look at the edges (as lots of commentators here claim to do/be), and don't have an appreciation of the difficulty and complexity of designing and manufacturing an optical train with those specifications, the WX may not seem that special.

I was looking for the wide field of view and it just wasn't there, it looked very pedestrian compared to my EII in terms of the AFOV. But Holger explained that the problem was probably the fully extended eyecups (something the guy who was helping me at the shop did before handing me the binoculars) which I assumed was the thing to do.

 

[JanPB]

Yes, the patent application contains lots of details. Thanks a lot, you should have a look into my book

Cheers,
Holger

Thank you for the link! Very interesting, lots of high-refractive-index glass in there looks like. Some time ago, in a fit of madness and mathematical nerd-hood, I implemented all of Buchdahl's aberrations in C++ (incl. aspherics and chromatics), wonder what it'll look like on those Nikons. Are patent data accurate in general or is there a bit of purposeful "fudging"? And speaking of books, Buchdahl's aberrations book should have won the Nobel prize in typesetting, it's flooring at first sight.

 

[Patudo]

I was looking for the wide field of view and it just wasn't there, it looked very pedestrian compared to my EII in terms of the AFOV.

again, I get that - if you're used to the Nikon EII 8x30 (8.8 degree field of view) the WX (9 degrees) represents only a slight increase. The WX gives you that 9 degree FOV at 10x magnification, but for some folks the difference between 8x and 10x magnification is not large. And quite a few folks here claim to be unconcerned about edge performance ("I only look at the center of the image"), so it doesn't matter to them that the WX image is sharp from edge to edge.

 

[Holger Merlitz]

Thank you for the link! Very interesting, lots of high-refractive-index glass in there looks like. Some time ago, in a fit of madness and mathematical nerd-hood, I implemented all of Buchdahl's aberrations in C++ (incl. aspherics and chromatics), wonder what it'll look like on those Nikons. Are patent data accurate in general or is there a bit of purposeful "fudging"? And speaking of books, Buchdahl's aberrations book should have won the Nobel prize in typesetting, it's flooring at first sight.

They offer 5 different eyepiece designs and don't tell which one was used (probably none of them). I would guess that example 2 is perhaps similar to the one used for the 7x50, and example 4 or 5 may be similar to the one in the 10x50 (the other ones can be excluded due to their distortion curves which don't match the properties of the binoculars). They never show all the design secrets in their patent scripts.

I fear Buchdahl is beyond my mathematical abilities ...

Cheers,
Holger

 

[JanPB]

again, I get that - if you're used to the Nikon EII 8x30 (8.8 degree field of view) the WX (9 degrees) represents only a slight increase. The WX gives you that 9 degree FOV at 10x magnification, but for some folks the difference between 8x and 10x magnification is not large. And quite a few folks here claim to be unconcerned about edge performance ("I only look at the center of the image"), so it doesn't matter to them that the WX image is sharp from edge to edge.

Thanks for the info. Very interesting.

 

[JanPB]

They offer 5 different eyepiece designs and don't tell which one was used (probably none of them). I would guess that example 2 is perhaps similar to the one used for the 7x50, and example 4 or 5 may be similar to the one in the 10x50 (the other ones can be excluded due to their distortion curves which don't match the properties of the binoculars). They never show all the design secrets in their patent scripts.

I fear Buchdahl is beyond my mathematical abilities ...

Cheers,
Holger

I suppose these days "fudging" the published specs is less "effective" because of the modern ease of computer optimisation. Out of curiosity I looked up Buchdahl's physics papers (he made some contributions to general relativity) and... they are completely normal! 🙂 I don't know what got into him when he wrote on optics.

 

[JanPB]

That is a good point. I think if you tried the WX 7x50 with it's 10.7 degree FOV, you would be more blown away by the large FOV.

Sounds like a quest: find those in a store somewhere.

 

[Tringa45]

I fear Buchdahl is beyond my mathematical abilities ...

For most of us who have read your book that is a very depressing conclusion!

Btw, what is the significance of the product of objective aperture and TFoV (450 mm°)?

Regards,
John

 

[Holger Merlitz]

For most of us who have read your book that is a very depressing conclusion!

Btw, what is the significance of the product of objective aperture and TFoV (450 mm°)?

Regards,
John

I don't see any useful application of this product - any ideas? TFoV times focal length approximately gives the size of the intermediate image (for small angles), and since the focal length kind of depends on the objective aperture (if the focal ratio is given), one might claim that the product of objective aperture and TFoV kind of defines the prism size, but it would be a far stretch

 

[wllmspd]

Holger. What is your PhD in? Where do you teach and do research? Is your interest in binoculars and optics just a hobby of sorts? I really appreciate your binocular reviews, and I generally always agree with them. Thanks!

Homepage Holger Merlitz I would say it’s a handy, but backed by plenty of numerical “clever stuff” ;-)

Peter

 

[JanPB]

A quick post-script: looked at the patent application that Holger provided a link to and have a couple of questions, very naive ones:

1. Why are those patents written in such a hyper-asinine fashion? Obviously there must be a legal reason for this, I guess this means the law is broken in some ways if it fosters this level of absurdity. Is it the same in other countries? Is this what Einstein had to read through while employed as a patent clerk in Bern?

2. Why are only the oculars described but not the objectives?

Surprisingly perhaps, that ocular, "Second Example" on pp. 15-16, (esp. its second group, surfaces 6-15) is amazingly well corrected for aberrations. For those who enjoy numbing the mind a bit, here is a CSV file (any spreadsheet app should read it) of that group, listing aberrations up to order 15 (the file says "Order N" for what modern terminology calls "order 2N+1" because that's the actual degree of the relevant power series term; so Seidel aberrations are listed under "Order 1"). Most of the gobbledygook is unimportant, the amazing thing are the numbers: very low, esp. in the higher orders which for average lenses can go into 10-digit figures and more.

Same thing for the chromatic aberrations (up to order 11 this time), those numbers are amazing. When examining older lenses, it's very clear that the designers checked the 3rd order aberrations and some of the 5th order but not higher as it's impossibly tedious to calculate them without a computer. So even great lenses like Ludwig Bertele's Biogon-like designs show a sudden increase above order 5, although the distortion (last row of each order) remains super low, for which those lenses are famous.

 

[adhoc]

JanPB, your info is very interesting, or, more precisely, should be after (if) I do some homework.

Now you know how Einstein's brain was exercised and toned for his discoveries. I guess with German compound-words it would be more spectacular. After this you can sort out the complexity of the universe.

To be fair by patent authorities, this is probably the result of decades of trial and error to achieve precision in both the legal and the technical dimensions. It seems to me that the English used in this worldwide does however also retains some archaisms. You may know that in the US to be a patent attorney one has to have a postgrad degree in a STEM field, apart from law school, and some (many?) have a PhD in such. (They also have special training.) I presume the wording required in a patent application is also due to input by such people.

 

[tenex]

Why are those patents written in such a hyper-asinine fashion? Obviously there must be a legal reason for this

Perhaps it's a game of balancing legally adequate description with trying not to make the specific recipe too easy to understand and learn from.