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Mike Rapchak
sage
Reged: 11/17/06
Posts: 450
Loc: Indiana, USA
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Hello,
Last month I reported on my new Vixen ARK 12x80 binoculars. I have since traded this wonderful instrument on a 16x80 pair (as good as the 12's are, with their 6.7mm exit pupil and my horrible NW Indiana skies I felt that a higher-power/smaller-exit-pupil model might better suffice).
I received the 16x80s yesterday (Fri. 12/29). Of course the "Cloudy Skies" curse immediately struck, waiting until sundown to get really nasty - an ugly cloud cover that hung overhead until tonight (not totally dissapating even to this moment).
However, sky conditions ended up at least marginally (desperately?) clear to where some stars were visible.
I debated posting this extremely cursory report since there really wasn't much to view. It was the performance of these binoculars that inspired me to do so anyway.
Compared to the 12x80s there wasn't a lot of difference - beautiful images of stars, well-defined and focused. The difference was, for one, in the image size. I know that a lot of folks prefer 20x, but from what I saw tonight I have no arguments against 16x. Afterall, binoculars aren't telescopes, and to me a wide FOV is desirable - that and minimum (but useful) magnificaton. IMO this pair of 16x80s more than satisfies both criteria.
With its smaller 5mm exit pupil (re the 12's 6.7mm) conrtast was improved - enough to where the difference was noticeable. Star images were delightful - sharp and bright enough yet no real hint of CA, spiking, or other aberrations (the #1 target star was Sirius!). I checked for edge-of-field distortion/light drop-off and, yes, they're there - but they're minimal. As I said in my previous test of the 12x80s, I'd estimate them to be no more than 5 percent of the overall FOV. It may be more than 5 percent, but the fact is that these aberrations are so slight that one does not notice them unless one is deliberately looking for them.
This initial test was done on the eastern sky: slight haze, pretty calm atomosphere. At this time I realized that choice objects like Orion, Taurus, etc., were not in my seeing window. So I went to one of my west-facing bedroom windows, cranked up the blinds, opened the window, and - high overhead there was the Moon - between half and 3/4 full (5/8?). There was a gauze of light clouds drifting over its surface - not enough to obscure details but sufficient to dim its glare a bit.
IMO the view of the Moon through these binoculars was, what word shall I use? Stunning? Yes, but "stunning" has a bit too much "punch", too much a sense of the spectacular. What I saw elicited that feeling that I'm sure we're all familiar with: a quiet sense of awe, a kind of gentle jaw-dropping where one sits there and can only breathe the word, "Wow". The colors/contrast were very pleasing. But the detail is what caused that sense of awe in me! 16 power may not be a lot, but the amount of detail at this magnification was wonderfully evident in these binoculars (particularly the craters!) - proof of the excellent optical quality of these binocualrs. And mind you, this was while hand-held and neck-straining for the view (the Moon was around 70 degrees up).
My first impression of these binoculars is that I've ended up with another winner. They're beautiful, magnificent (sorry). My test was done in a totaly objective mindset. It was the views I got - particularly those of the Moon - that caused me to finally (understandably) shift into the emotional, the final result of my experience. Thus my thrill with this instrument's views came after my most objective analysis.
I wil do a more thorough test (star clusters, DSOs, etc.) when sky conditions permit and will report my findings for anyone intersted. Suffice to say that these binoculars produced what one would expect from such an instrument at such a price (I actually consider them a bargain at $560). Views are crisp and bright with good contrast. Very good eye relief (comfortable for me with eyecups nearly fully extended [I do not wear glasses]). Though basically hand-holdable for very short periods a tripod is strongly advised.
Conclusion: I recommend these 16x80s without reservation.
Mike Rapchak Jr.
P.S. I do not work for nor am I in any way affiliated with Vixen Optics.
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edwincjones
Post Laureate
Reged: 04/10/04
Posts: 4423
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I may have missed it, but are the 16x80 Vixen also?
Good review, thanks for posting it.
edj
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n w arkansas
Binocular, Solar, General Amateur Astronomy
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camvan
Carpal Tunnel
Reged: 05/02/05
Posts: 2086
Loc: British Columbia
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I think you missed it edj...it says 'Vixen 16x80 Binoculars' right in the subject line 
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Cameron
"Aperture can only be replaced by even more aperture. Dark transparent skies cannot be replaced by anything else." - Stathis Kafalis
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edwincjones
Post Laureate
Reged: 04/10/04
Posts: 4423
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too early, too little coffee
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n w arkansas
Binocular, Solar, General Amateur Astronomy
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Mike Rapchak
sage
Reged: 11/17/06
Posts: 450
Loc: Indiana, USA
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edj,
My fault. I re-read what I wrote last night and except for the the subject line (as Cameron so graciously explained) the fact that these are Vixen 16x80s isn't actually specified in the text. 
Mike R.
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Erik D
Carpal Tunnel
Reged: 04/28/03
Posts: 2554
Loc: Central New Jersey, USA
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Mike,
Congrats on your new purchase. Having several pairs of bino from 12X50 to 25X100 in my inventory I am able to experiment with different combination of magnification, exit pupil and FOV for star gazing.
I've found that I enjoy the darker sky background in my binos with 4-5mm exit pupil from my sub magnitude 5 backyard. I also enjoy using higer power binos as long as the objects I am viewing fits comfortably in the FOV. Orion used to stock both 16X80 and 20X80 model Japanese binos several years ago. FOV of the 16X and 20X models were both listed as 3.5 deg. The Orion Megaview 15X80 also had the same 3.5 deg FOV.
http://www.excelsis.com/1.0/entry.php?sectionid=21&entryid=150
Since those 15/16X 80mm models did not offer a wider TFOV than the 20X I elected to go with the 20. Looks like your 16X80 Vixen has wider 4.3 deg FOV. That means you can cover ~50% more sky AREA compared to 3.5 deg. Should be a good combination of FOV, maganification and exit pupil if you have a chance to observe from dark sky locations.
Erik D
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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 12581
Loc: Cumberland, R I , USA42N71.4W
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Quote:
Looks like your 16X80 Vixen has wider 4.3 deg FOV.
Rarely do we ever see a binocular advertised at 70° Afov that actually turns out to be 70°.
Even more rarely do we see a binocular with 70° Afov that is well corrected in the outer fov. Simply because it is very difficult to make well corrected 70° eyepieces, and especiallly to put two of them in a reasonably priced binocular.
It would be interesting if this were such a model.
Here's a few easy measures to check
4.0° 7 UMi to 15 Umi, not completely across the top of Little Dipper Cup
4.1° 23 Dra to 33 Dra, Beta to Gamma draco, south side of Draco head
4.3° 10 CMi to 3 CMi, alpha (Procyon) to Beta Canis Minor
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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camvan
Carpal Tunnel
Reged: 05/02/05
Posts: 2086
Loc: British Columbia
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could someone be so kinda as to give a quick formula and explanation of how you figure out your FOV and AFOV? is the way it's calculated the same for all optics, or is there an impact being you are looking thru two OTA assemblies?
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Cameron
"Aperture can only be replaced by even more aperture. Dark transparent skies cannot be replaced by anything else." - Stathis Kafalis
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Erik D
Carpal Tunnel
Reged: 04/28/03
Posts: 2554
Loc: Central New Jersey, USA
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Cam,
This is one of the easier calculations in optics. Apparent FOV is simply the True Field of View times magnification(or power).
A 20X binocular with 3.5 deg FOV will have APFOV of 20X3.5= 70 deg.
Most binoculars list TFOV or how many feet/1000 yards. For example my Eagle Optics 8X32 has FOV of 393 ft at 1000 yds. One deg FOV is ~52.4 ft/1000 yards. My EO has TFOV of ~7.5 deg or 60 deg APFOV.
Mike's Vixen 16X80 is listed as having FOV of 4.3 deg. APFOV is 68.8 deg. Fairly wide for a EP.
I usually prefer my binos to have at least 60 deg APFOV. EdZ measured the Burgess 20X80 LW to have 3.8 deg TFOV sometime ago. That's very wide 76 deg APFOV. Do expect edge distortion with such wide angle binos. My Celectron Nova 7X50 is listed as having 10 Deg TFOV/70 deg APFOV. It's almost like viewing thru a fisheye lens at night. Stars in the outter 20% of the Field are totally distored.
Erik D
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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 12581
Loc: Cumberland, R I , USA42N71.4W
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Quote:
This is one of the easier calculations in optics. Apparent FOV is simply the True Field of View times magnification(or power).
A 20X binocular with 3.5 deg FOV will have APFOV of 20X3.5= 70 deg.
Most binoculars list TFOV or how many feet/1000 yards. For example my Eagle Optics 8X32 has FOV of 393 ft at 1000 yds. One deg FOV is ~52.4 ft/1000 yards. My EO has TFOV of ~7.5 deg or 60 deg APFOV.
Mike's Vixen 16X80 is listed as having FOV of 4.3 deg. APFOV is 68.8 deg. Fairly wide for a EP.
Yes, this is an easy calculation. But maybe 7 out of 10 binoculars do not measure up to the Tfov specs as listed. So you can't trust the specs. We've known that here for a long time. That's why I have given the needed information to actually measure the TFOV. I would love to have my suspicion proven wrong.
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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Mike Rapchak
sage
Reged: 11/17/06
Posts: 450
Loc: Indiana, USA
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Edz,
Many thanks for the intersting comments re FOV. I haven't yet attempted to determine the TFOV of my Vixen 16x80s bit will do so as soon as I get some decent weather (last night's relatively clear skies were the first in over a week; as of today we're back to the normal "gloom & doom" conditions).
I've also been curious about Vixen's specs that show the 16x80s as having a slightly wider TFOV (4.3 degrees) than the 12x80s (4.1 degrees). I don't know this is a simple typo or if it is true. I would assume that magnification and TFOV in binos with the same size objectives are determined by the EPs. I really don't know what the story is with the Vixen's EPs, but what I find intersting is that the EP-lens diameter on both the 12x80s and the 16x80s is essentially the same - around 7/8". Whether or not this means that the same EPs are used on both pairs I can't say.
Then there is the matter of focal length/ratio. Measuring the distance between the objectives and the EP lenses (with a steel scale held alongside one of the barrels) I get a length of right around 11 inches. I may be mistaken, but IIRC this is a bit shorter than the measurement I got on the 12x80s.
I'm sure that you can help clarify this situation and I'll be very interested in your thoughts/comments (as well as those of others here).
Mike R.
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Mike Rapchak
sage
Reged: 11/17/06
Posts: 450
Loc: Indiana, USA
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Many thanks, Erik! I have a feeling that, as you say, once I get these binos out under a dark sky I'm going to be thrilled by their performance. 
Mike R.
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Mark9473
Carpal Tunnel
Reged: 07/21/05
Posts: 2699
Loc: 51°N 4°E
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Great report Mike, I'm looking forward to more.
Oh, and by the way, happy New Year everybody!
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Mark
Leica 8x20; Vixen 8x42; Swift 8.5x44, 10x50 and 20x80; TS 7x50; Orion 15x63
WO Megrez II 80 FD + Baader 90° T2 Amici
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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 12581
Loc: Cumberland, R I , USA42N71.4W
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Mike, you can't really tell anything by those measures. There is no way of knowing what the focal length of the eyepieces is, and they could very well be different, even though they have the same eye lens diameter. The entire line of Radian eyepieces all have the same eye lens diameter.
Based on the dimensions given in the spec sheets, it looks like they use the exact same body for the 12x, 16x and 20x, possibly even the 30x with a slight extension. That would mean only the eyepiece changes.
Binoculars are almost always around f/4 and an 80mm binocular may be longer, at least f/4.5. So a reasonable assumption is the focal length is about 350mm. Using eyepieces of varying focal lengths is all that is required to change magnification. Varying the Afov, or the field stop diameter, of the eyepieces, will change the field of view or Tfov. So they could use eyepieces such as 29mm, 22mm, 17.5mm and 12mm.
Several things happen when you increase the field stop in an eyepiecce. You get a wider field of view, but you also generally increase the aberrations in the outer field of view, including coma, spherical aberration and astigmatism. This is not just binocular eyepieces I'm talking about, this is eyepieces in general. Most 70° eyepieces on the market today have pretty poor outer field performance. It takes a very well corrected eyepiece to eliminate those aberrations, and it cost considerable money to make such eyepieces. So generally what we see in binoculars that have 70° Afov is pretty poor performance in the outer field of view, unless perhaps you are using a $300-$400 pair of eyepieces.
Few binoculars have well corrected wide fields of view. The Fujinon 16x70 is one that is fairly well corrected. It has a true measured Tfov of 4°, therefore the eyepieces have an Afov of 64°. It's well corrected to within 20% of the edge, or 80% out, maybe 85%.
You estimated sharp view of the Vixen Ark to within 5% of edge. Likewise you estimated the 12x80 to have a sharp view to within 5% of the edge. Frankly Mike, I can think of only one or two binoculars that might even come close to that. The Pentax 16x60 was one, it is sharp out to 90% of the field, but it has orthoscopic eyepiecs with a 42° Afov, not wide angle eyepieces. That's about what I would expect from orthoscopic eyepieces. It is not what I would expect from 70° eyepieces.
Two prior reviews of these vixens, one a 16x80 and one a 20x80, report loss of usable field in the outer 20% or more of the field. None of the prior reports gives us any true measure of the field of view.
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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Mike Rapchak
sage
Reged: 11/17/06
Posts: 450
Loc: Indiana, USA
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Brief Update:
At approx. 5:15 p.m CST I did a short check of the Moon through the 16x80s. I realized that last night's description of the Moon's phase was inaccurate; it's actually a good 3/4 full.
Miraculously the skies have cleared off nicely. It isn't totally dark yet (the sky - aided by the Moon's glow - is a soft, dark blue).
This time there were no thin clouds to help tame the Moon's glare. But this turned out to be a non-issue afterall.
Once again my immediate reaction was delight at the crisp, detailed view of the lunar surface through these binoculars. While not particularly large at 16 power, the view was very impressive . Even with its face-on glare the visible details on its surface were striking in their fine resolution.
Again checked for distortion and light fall-off at the edges of the field, and also ghosting/flaring/chromatic aberration - all while viewing "der Mond".
Either I am going blind or these binoculars are quite a superior optical instrument. Glare is slightly noticeable, and there is some false-image ghosting that seems concentrated in the lower left edge of the FOV (around 8 o'clock). I find these artifacts acceptable considering the magnitude of the glare (brilliant) from the Moon's surface. I don't recall ever using a binocular that didn't exhibit at least some of these effects. I perceived no appreciable light drop-off at the edges. There is a bit of image distortion, but it's a the extreme edge and not an issue unless one is deliberately looking for it.
And CA? Simply put, it isn't there. Beleive it or not, there is none - none that I saw. Of course in its present phase the Moon is nearly round. Perhaps if there were a crescent limb to observe I might see a trace of CA. But no trace of any as of yet.
So far these binos appear to be very capable performers. They are quite comfortable to view through and IMO offer a more than adequate FOV. Star colors are very nice (as are the contrasts in colors on the lunar surface). I can't say how good these are in comparison to other binos since I don't own any (other than a splendid vintage pair of Celestron Nova EWA 10x50s which exhibit a similar though considerably smaller view. Star colors are also weaker in these than in the Vixens).
This is where things stand at the moment. I'm still working on determining these binos's TFOV. Hopefully I'll have something to report before long.
Mike Rapchak Jr.
Edited by Mike Rapchak (01/01/07 07:17 PM)
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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 12581
Loc: Cumberland, R I , USA42N71.4W
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Happy New Year Mark, and Mike, and Erik and everyone else too.
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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Mike Rapchak
sage
Reged: 11/17/06
Posts: 450
Loc: Indiana, USA
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Edz,
Many thanks - and the same to you and to yours! 
Mike R.
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Mike Rapchak
sage
Reged: 11/17/06
Posts: 450
Loc: Indiana, USA
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Many thanks, Mark - and the same to you and to yours!
Mike
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Mike Rapchak
sage
Reged: 11/17/06
Posts: 450
Loc: Indiana, USA
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Ed,
Again I may be off on the 5% figure, but the affected area is so small that I never notice it unless deliberately testing for it. I just ran out and checked again viewing the Moon. Honestly, I do not detect any visual light drop-off at the edge of the field. There is a bit of image distortion but again it's way out at the edge where it normally isn't noticeable (and trying to gauge it accurately with the Moon at the edge of the viewable field is great for inducing eyestrain! ).
Now, concerning TFOV: What is the star at the apex of the Hyades? Y Tauri? Well, it and Aldebaran just barely fit into the FOV. As yet I don't know what the distance is between these two stars, but whatever it is, that is the TFOV of these binoculars.
Mike R.
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EdZ
Professor EdZ
Reged: 02/15/02
Posts: 12581
Loc: Cumberland, R I , USA42N71.4W
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4.0° from a 87 Tau to y 54 Tau Aldeberan to the point of the V in the Hyades
edz
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Teach a kid something today. The feeling you'll get is one of life's greatest rewards.
member#21
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Mike Rapchak
sage
Reged: 11/17/06
Posts: 450
Loc: Indiana, USA
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Ed,
That's it. Thank you. 
Mike
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Erik D
Carpal Tunnel
Reged: 04/28/03
Posts: 2554
Loc: Central New Jersey, USA
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Quote:
Ed,
Again I may be off on the 5% figure, but the affected area is so small that I never notice it unless deliberately testing for it. I just ran out and checked again viewing the Moon. Honestly, I do not detect any visual light drop-off at the edge of the field. There is a bit of image distortion but again it's way out at the edge where it normally isn't noticeable (and trying to gauge it accurately with the Moon at the edge of the viewable field is great for inducing eyestrain! ).
Mike R.
Mike,
I normally check for edge distortion or field curvature by placing a fairly bright star(~mag 1.5/2) at the very center of the field. Fine tune the focuser to get the star to the sharpnest point possible. Then I pan the binocular to move the same star outward left, right, up or down towards the edge of the field. I observe the star to estimate the location or % from center where the star starts to spike or flare.
Using a point source to check edge sharpness should work better than observing the moon. You can try this with Jupiter or Saturn too to see at how far out from center their disk starts to distort as you move towads the edge. IMO, the moon, at ~1/2 deg, is too large an object for checking edeg sharpness.
Since I almost always place the DSO I wish to observe near the center of the field I can tolerated minor distortion or fall off in brightness at the very edge....as long as stars don't turn into seagulls. I usually prefer a 70 deg wide angle with minor edge distortion than a narrow field bino with ~50 deg APFOV.
Almost all of my binos 26-50mm binos designed for terrestrial use exhibt field curvature. Pin point stars at the center starts to losse focus about 70% from center but can be re focused back to a point. Some extra wide angle binos show other edge distortion that can not be corrected by refocusing.
As EdZ said, even premium giant bino 70mm and up starts to show some edge distortion beyond 75% from center. IIRC, I think the $1,200 Takahashi 22X60 with it's very narrow 2.1 deg FOV show edge distorttion near the outter 10%. The Tak 22X60 has just 46 deg APFOV. The best astro bino I have looked thru is the Miyauchii Saturn III with 66 deg APFOV, I notice minor flaring by 90% from center but stars are still recognizable as point source. The Saturn III is a F7.5 system and cost $2,600.
Erik D
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Mike Rapchak
sage
Reged: 11/17/06
Posts: 450
Loc: Indiana, USA
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Erik,
I wholeheartedly agree. The problem yesterday evening was that, other than Aldebaran, there were no bright stars visible when I did my tests. I can see where the Moon, being a large, extended object, can be less accurate for such a test. What I did is to try and observe the very edge of the moon as it approached the edge of the FOV (i.e., the right-side edge as I moved it to the right-side edge of the FOV, and vice-versa). I was able to see a bit of distortion at the edge[s], but IMO it was minor. And since no one observes the Moon at the extreme edge of FOV (particularly a generous 4-degree FOV) this minimal distortion is for all practical visual purposes non-existent.
However, as your statements imply, stars are a different visual matter - especially stat clusters, star fields, etc. This is where edge distortion will be noticed, and if excessive, annoying. Though I wasn't paying strict attention to edge-distortion levels while viewing stars, I never noticed them while viewing. This is not to imply that they aren't there; it's just that it is negligible in this particular 16x80 bino. At the time of viewing the only easily visible large stellar asterism was the Hyades. Although most of my attention was focused [n.p.i.] on image quality and trying to determine true FOV, I noticed no serious image distortion at or near the field edges (please refer to earlier posts in this thread dealing with true FOV. I can just squeeze the Hyades into this bino's FOV).
My feelings are that this is one very satisying optical instrument. The views are wonderful, and the experience is quite comfortable and relaxing visually. Not as much as, say, my Celestron 10x50s, but that's to be expected from a much smaller, lighter bino with large EPs and an incredible "space walk" 8-degree FOV (now HERE is an instrument with noticeable edge-of-field image distortion; yet it is never a major annoyance since one's attention is always on the center-of-field view - and the jaw-dropping wide, borderless "window" effect while scanning asterisms, star fields, the Milky Way, etc.).
When the next opportunity arises (the new-instrument-purchase/cloud-demon curse is running full bore here in NW Indiana) I will do the test on at least one bright star. Siruis is easily viewable at this time of year, as are other bright stars (thrue, Aldebaran is there but I'd prefer something a bit brighter).
Mike R.
Edited by Mike Rapchak (01/02/07 02:47 AM)
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Mark9473
Carpal Tunnel
Reged: 07/21/05
Posts: 2699
Loc: 51°N 4°E
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Mike, the last thing you want to do is take a satisfying optical instrument and go to lenghts to understand every minor shortcoming it may have, thereby eliminating your satisfaction. But I'm also sure that by now you know that we on this forum love to discuss these things, especially since they are relevant to other prospective buyers. So thanks for your efforts! 
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Mark
Leica 8x20; Vixen 8x42; Swift 8.5x44, 10x50 and 20x80; TS 7x50; Orion 15x63
WO Megrez II 80 FD + Baader 90° T2 Amici
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Erik D
Carpal Tunnel
Reged: 04/28/03
Posts: 2554
Loc: Central New Jersey, USA
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Mike,
You may want to try other stars besides the brightest such as a Sirius or Vega when you are testing an achromat. I am not an expert on optics testing but I know those Magnitude 0 stars can be very challenging targets for some of the best APO refractors. I expect you'd see spikes & false color on Sirius at the center of a well corrected achromat no matter how carefully you fine tune the focus.
The belt stars of Orion or the main stars of Cassiopeia could be better targets. Mintaka in the belt of Orion is mag 2.2 with mag 6.7 double 53 secs away. Should be a good one in your 16X.
I have not seen the new Vixen 80mm binos first hand but from the product photos they look like well made Japanese binos with very good fit and finish. I am glad you found a model you like. Please keep us posted if you have a chance to compare them with a good quaility Chinese 80mm.
Erik D
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Mike Rapchak
sage
Reged: 11/17/06
Posts: 450
Loc: Indiana, USA
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Mark,
You certainly hit the nail on the head with your comments! While for myself it's true that I'm not as concerned about technical/visual minutiae with binoculars as with telescopes, it's the tradition here on Cloudy Nights, one that I find quite interesting and VERY infomative. Also, the fact that all of us are genuinely concerned with the performance of existing equipment - especially those who are potential purchasers - is to me of paramount status. Thus, I'll do my part to contribute helpful information to the best of my ability. I'm no 'rocket scientist' by any stretch of the imagination, but I can at least describe what I see.
And, thanks to all the wonderful folks here on Cloudy Nights, I now know more about binoculars, telescopes, EPs, mounts, etc., than ever before. My desire is to share my experiences and to do so as objectively as I can from the technical standpoint, but it is also to describe these experiences in the subjective/aesthetic realm, which I think is always the bottom line with us stargazers and what "hooked" us all in the first place (there is nothing so awe-inspiring, so exotic, as a view of the night sky through a good optical instrument).
Mike R.
Edited by Mike Rapchak (01/01/07 04:50 PM)
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Mike Rapchak
sage
Reged: 11/17/06
Posts: 450
Loc: Indiana, USA
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Erik,
Yes, I agree. Many lesser than 0-magnitude stars will suffice. Thr problem right now is our weather. I think we've had four or five clear nights in the past month[!]. Yesterday evening we were blessed with clear skies for approximately two hours. I was going to do more testing around 8 p.m. but by that time the clouds had once again covered the entire sky (rats!). Today it's the same thing. Perhaps we'll get a bit of clearing again tonight. 
I also feel that the Vixens are a VERY well-made instrument. They have a wonderful solidness to them that is impressive and to me their overall size/balance is ideal. Center-focus and right-eye diopters are great - just the right amount of tension/resistance and no noticeable slop or backlash (this was also true of the 12x80s I had). At the moment I forget the eye-relief spec, but for me it's fine - even better than the almost-too-generous amount of the 12x80s. Although I don't wear glasses when viewing, I find the range more than adequate in both directions. The adjustable screw-up eyecups are a great help here since one can custom-set his/her optimum eye-relief distance.
And the views are, in a word, beautiful. For a while I wondered if 16x would result in too small a FOV, minimizing the "enchantment" of a wide-field binocular view, but no, there is no such disappointment. To me 16x (through an 80mm lens) is about ideal. Objects viewed are of adequate size, yet the FOV is still large enough (4 degrees) to provide that "space walk" effect.
One thing that concerned me when I first ordered the 12x80 pair was how the field would appear through them. By this I mean: In 1978 I purchased a similar-sized pair of University Optics 11x80s. A fine instrument in its own right (there's a thread here somewhere devoted to these and titled something like "UO Comet Kings"). However, these UOs had an artifact that I found very annoying and dissatisfying: the view through them was like looking down a short dark tube, or viewing through a port hole in a wall maybe 10" away from your eyes. Not being knowledgeable of the causes of such a view at the time I ordered the Vixens (November of last year - wow, it's "last year" already! ) I wondered if the Vixens would be similar. Happily, and much to my great releif, they aren't. Views through them are similar to those through my extreme-field Celestron Nova 10x50s - even though the FOV is only half of the Celestrons.
So far I've had no opportunity to look through any Chinese-made 80mms. The acquisiton of my Vixens is a bit of a tale (not to bore you here!): I'd orignally purchaed a pair of Zhumell 25x100s (this past October). So far these are my only experience with Chinese-made instruments. Other than country of origin, I don't imagine that a comparsion between these and any as-yet-unseen-by-me 80mms would be accurate. My point here is optical quality; tragically the big Zs didn't cut the mustard. After searching the website of the dealer I'd gotten these monsters from I discovered the Vixens, did some serious self-analyzing (real priorities re bino viewing) and exchanged the Zs for the Vixen 12x80s. To make a long story even longer: While I found the Vixen 12's a beautfiful instrument I realized that its exit pupil and my terrible skies made for less-than-ideal views. Thus I exchanged the 12s for the 16s. IMO the 16s are even more of a joy to use than the 12s.
Now, subsequent to receiving the 12s and while considering a more powerful model with smaller exit pupil I stumbled upon the Garrett 15/20x85s. Priced similar to the Vixens, I decided to swap for them. Unfortunatley the dealer doesn't carrry the Garret line, so I was restricted to their offerings. If they did indeed carry the Garrets I probably would have ended up with the 15x85s, and would then be able to comment on them (Chinese) as compared to the Vixen 12x80s I'd had (Japanese).
As things stand I've now had the opportunity over a short period of time to use not one but two pair of big Vixen 80mm binos and I can state, for what it's worth, that I have found no variation in quality between them. They are both very fine, eminently satisfying instruments mechanically and visually, and to me worth their price. In this respect I have no regrets over the fact that I did not end up with the Garretts (not meant as a knock against Garrett!).
Mike R.
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