Does Anyone Else Love 15x Binoculars? (1 Viewer)

Ed,

I've done this experiment a few different ways, but today I stood outside with a small magnifying hand mirror. The eye shield this time was a rubber eyecup from an old CJZ 7X40. I placed the eyecup to my left eye. It does a pretty good job of blocking peripheral light while leaving the center 70 degrees of the visual field unobstructed. Even though it is overcast today my unshielded right eye was closed to about 2-3mm, while the left eye was obviously shadowed by the eyecup and opened to 3-4mm. I reversed eyes and checked both eyes with and without the eyecup. The numbers are estimates, but the visible difference in dilation is quite obvious.

My only point in mentioning this experiment was to suggest that whatever data exist in the ophthalmological literature on the normal dilation of the eye under different lighting conditions would probably not be good predictors of dilation when a binocular is placed in front of the eye. This doesn't change the relationships of binocular configurations, but it might indicate that the eye can take advantage of large exit pupils at higher than expected light levels.

The results do suggest to me that binocular eyecups which do a good job of blocking side light should, under some lighting conditions, cause the eye to open wider than it would if the side light were not effectively blocked (as when eyeglasses are worn with the same binoculars); giving us yet another source for subjective disagreements about "brightness" in particular binoculars.

Henry

Selling your Swarovski 15x56 SLC ??

After you posted this very positive recommendation, along with several other similarly enthusiatic endorsements, I am surprised to see you are selling your primary birding binoculars on Ebay.

Please tell us why you have changed your mind about them.

Good luck on the sale, and good birding with whatever you are still using.

angelo225544 said:

I recently bought a used Swarovski 15x56 SLC binocular. They were priced so well ($1100) that I figured I could sell them for more than I paid even if I didn't like them. Most of us, I'm sure, have read again and again that 15x is simply too much magnification to hold steady. I was shocked to discover that even with the incresased shake I can see alot more detail than with my 8x or 10x. I soon realized that these should be my primary birding binocular. The Swarovski's have an unusually wide FOV at 4.4 degrees (231 feet at 1000 meters) which helps enormously but the huge surprise for me is how usable and addictive the magnification is. Does anyone share my love of high magnification?

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Joel said:

After you posted this very positive recommendation, along with several other similarly enthusiatic endorsements, I am surprised to see you are selling your primary birding binoculars on Ebay.

Please tell us why you have changed your mind about them.

Good luck on the sale, and good birding with whatever you are still using.

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Thank you for asking, Joel. As I stated in my original post, I purchased my first 15x with every intention of selling them. However, after being as impressed as I was with them, I purchased a 15x56 SLC New version and sold the older version. The newer version is optically nearly identical and slightly lighter. I have also just purchased a Canon IS 18x50 which I'll be comparing to the Swaro's for both birding and astronomy.

Henry,

Thanks for explaining your method. I'll try to replicate your observations, but may be hampered by being far sighted. Anything that close takes eyeglasses, but maybe it will work with glasses. Wouldn’t you be surprised.

I have no doubt that your statement is true:

... normal dilation of the eye under different lighting conditions would probably not be good predictors of dilation when a binocular is placed in front of the eye.

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When developing my infamous EBBS simulator a year or so ago, it became clear that this is probably universal because binoculars necessarily limit the field of view and along with it the total amount of light energy stimulating the retina. I assumed that for a standard eyecup, with whatever side leakage, the ambient light pupil-diameter function in the literature could be adjusted on a linear basis, — in essence with the pupil responding to a “corrected” illumination. Real life is probably more complicated.

Frankly, I am a bit perplexed by:

... eyecups which do a good job of blocking side light should, under some lighting conditions, cause the eye to open wider than it would if the side light were not effectively blocked (as when eyeglasses are worn with the same binoculars…

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Your procedure did not compare an eyecup alone with eyeglasses plus eyecup, or eyecups of different leakage. So, I feel the conclusion is perhaps somewhat of a reach.

From my perspective, the observed increase in pupil size is parsimoniously explained by less total light energy entering the eye. The effectiveness of eyecups to eliminate sidelight, the reduced field of view that binoculars necessarily produce, “binocular rivalry” when one eye is presented with a different picture than the other, are other factors that need to be taken into consideration for a more complete explanation of how the pupils work with binoculars.

Let me add that I believe knowledge of such pupil dynamics is the most important single issue remaining to be understood for binoculars, and I fully agree with your suggestion that it might well account for several discrepant opinions about brightness — as well as acuity. So, I applaud your efforts and hope these comments are not offensive.

For some time I've been using tubes of different length to simulate (i.e., with no glass) the FOV of a 1x telescope. My interest has been the perceived brightness of the illuminated field; however, I've concluded it would really be better to use two tubes (i.e., simulate 1x binoculars) and thereby avoid binocular rivalry problems. I haven't had time to construct a good apparatus, but the tubes should be parallel and allow a range of extension to control a calibrated FOV. Provision for neutral density filters would also help. I haven’t figured out how to observe pupil diameter though. :stuck:

Ed
PS. When using a tube I've found that a better sidelight seal can be gotten by cutting the tube at a bias of about 18 deg. This produces a Zeiss Victory type setup.

I have a Minox 15x58 BD ED, bought second hand for 600 € here in Italy where I live; surely, the high magnification is amazing, optically the Minox I own (and the 15x56 Swarovski certainly) is superb, but the price to pay for this is a heavy bino to hold (the problem is to carry it for an entire day; mine is 1490 gr !) . If I must walk for an entire day, I take with me a binocular light and optically superb (Trinovid 7x42 or 10x42 or Swaro 8x30SLC ). I bought my 15x58 only because I found it used (and after tried it at my local store, the viewing was very OK), but at normal price, I think absolutely I would not buy it.

angelo225544 said:

I recently bought a used Swarovski 15x56 SLC binocular. They were priced so well ($1100) that I figured I could sell them for more than I paid even if I didn't like them. Most of us, I'm sure, have read again and again that 15x is simply too much magnification to hold steady. I was shocked to discover that even with the incresased shake I can see alot more detail than with my 8x or 10x. I soon realized that these should be my primary birding binocular. The Swarovski's have an unusually wide FOV at 4.4 degrees (231 feet at 1000 meters) which helps enormously but the huge surprise for me is how usable and addictive the magnification is. Does anyone share my love of high magnification?

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Angelo,

I don't believe in much more than 10x for handheld use. I realize that you (and even I) can see more details with 15x than with 10x for a limited time. But what happens when you get tired in your arms? Even if one can accept more handshakings it's also a question of comfortability, the handshakings make me tired in my head quite soon even with 10x power.
I will say you are unique if you in the long run will continue to love 15x for handheld use. That doesn't mean you are wrong, some people have exceptional abilities! Among many competent users 15x power related to such heavy binoculars is defined as "has to be tripod mounted".

BUT, as a complement to a lower power binocular as a short-time handheld instrument, mainly used with a monopod I think a 15x56 is great!

Regards, Patric

Thanks to Joel, who posted this on todays thread "Swarovski's 7 x 25??," here is a magazine article on the benefits of carrying and using lightweight but quality 8 x 30/32's.
http://grayssportingjournal.com/stories/022306/shooting.shtml

Read it before you decide to spend big bucks on big power.
Bob

ceasar said:

Thanks to Joel, who posted this on todays thread "Swarovski's 7 x 25??," here is a magazine article on the benefits of carrying and using lightweight but quality 8 x 30/32's.
http://grayssportingjournal.com/stories/022306/shooting.shtml

Read it before you decide to spend big bucks on big power.
Bob

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Bob,

I found that to be a very pedestrian review. The author wanted to be clear in his opinion, which he was but he focussed on portability as the major advantage of the 8x30/32 class and did not admit to any optical advantage of the larger binoculars. I would guess that hunters abuse their optics more than bird watchers, but not by much. Even for hunters, his audience, there is a strong desire to see "more" before sunrise and at dusk. Although, modern coating makes today's 8x32 as good as the last generation's 8x40, at those times of the day, an 8x40 or even a 10x40 may be advantageous, even to bird watchers. Another contributor to this forum has praised the 8.5x44 Audubon for just that reason.
Having written that, I most often chose my Zeiss 8x40 over a Nikon 8x30 EII, on the basis of weather. Cloudy days are dimmer and may bring rain, so the waterproof Zeiss has a double advantage under such conditions. Indeed, the modern 8x30/32 will handle most of our needs but not all the neeeds of all bird watchers.

Happy bird watching,
Arthur Pinewood :scribe:

Arthur,
I agree to the extent that it would be advantageous for birders and casual hunters to have a 2nd pair of bins with a large exit pupil. I have a couple myself but I don't use them often. I still pull out my old Leica Trinovid 7 x 42's on dull, rainy days but 90% of the time I'm using my Nikon 8 x 30 EII's or 8 x 32 LXL's.

To be sure, the author's line of work will put him and his binoculars into conditions few of us will experience; which is why he is making his argument in favor of the 8 x 30 format. They have been tested under rigorous conditions and passed. It's just one more reason people choosing their first binocular should give very serious consideration to the 8 x 30/32 format and then build from there. Their optical, durability and ergonomic bugs have been largely worked out, and they are very user friendly.

Cordially,
Bob

ceasar said:

Arthur,
Their optical, durability and ergonomic bugs have been largely worked out, and they are very user friendly.

Cordially,
Bob

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Except where eye relief is concerned. In this respect they remain relatively poor. Even the top of the line Leica Ultravids costing over $1500 only manage between 13 and 13.5mm of eye relief. The 10x32 Swarovski EL has only 12mm and the 10x32 Leupold Katmai has an abismal 10.2mm. If you wear eyeglasses you need to take special care to ensure this class of binocular will really give you the performance you desire because, in many cases they will not.

Lucznik,
The author of the article is writing about 8x only. 10x usually have shorter ER. I've made a comparison of the weight, FOV and ER of fourteen 8 x 30/32 bins. (13 roof prisms and the Nikon Superior E) I got the figures from Eagle Optics catalog. 12 of the 14 have ER of 15mm or more and 9 of those are 16mm or better. (Ultravids are 13mm and Zeiss Conquests are 14.5.)
12 weigh under 22 oz. and of those 6 are under 20 oz.
10 have FOV's of 390' or more.

You can find some fault with any of them but you will be hard pressed to find this kind of overall user friendliness in other sizes and formats.

Bob

ceasar said:

Lucznik,
The author of the article is writing about 8x only. 10x usually have shorter ER. I've made a comparison of the weight, FOV and ER of fourteen 8 x 30/32 bins. (13 roof prisms and the Nikon Superior E) I got the figures from Eagle Optics catalog. 12 of the 14 have ER of 15mm or more and 9 of those are 16mm or better. (Ultravids are 13mm and Zeiss Conquests are 14.5.)
12 weigh under 22 oz. and of those 6 are under 20 oz.
10 have FOV's of 390' or more.

You can find some fault with any of them but you will be hard pressed to find this kind of overall user friendliness in other sizes and formats.

Bob

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Field of view and weight are indeed, both quite good in this class. Though that weight reduction does not always make the binocular all that much smaller in physical size. Certainly no binocular in the 30-36mm class can be considered a "pocket size" optic (except for maybe in a jacket which is not always comfortable to wear.) Usually the user has to wear them about on the neck or shoulders using the same straps as a they do with a full size binocular. Thus, the claims of added portability are somewhat suspect (especially if the hunter is using a quality harness system as they should.)

The light gathering abilities of these 30+mm objective lenses may indeed be impressive but, to claim they are the equals of other high quality glass with 40+mm objective lenses just because they might cost somewhat less, is a marketing gimmick that has no basis in reality. Its similar to the oft-heard claim that a 10x25mm Leica Ultravid is as bright as full size optics. The laws of physics simply contradict such claims. They may be bright and they may even be as bright as a particular person needs but, they cannot be as bright as quality glass of any significantly larger size. Similarly, the drop in objective lens size by definition means that you lose some of the resolving capacity of the optics. That means less detail can be seen, period. This loss may or may not negatively affect a particular person's needs or uses and many people (myself included in many circumstances) are perfectly happy to trade some optical performance for added portability and convenience but, it is there nonetheless.

The author may have been focusing on the 8x magnification but, he was also presenting them as the absolute solution to all "casual" hunting situations - which is absurd. Here in the wide open expanses of the Rocky Mountains it doesn't take long for many hunters to decide that the extra magnification of a 10x glass is very, very welcome. Thus, the consumer making such a decision needs to know that in 10x the eye relief for this class of binocular goes from Sort-of-OK to down right abysmal in a hurry. Furthermore, since the author made a point of singling out the Leica Ultravid as his personal choice in this class, the eyeglass wearing consumer should be made aware that even in the 8x, this particular binocular has only 13mm of eye relief and would likely be a big dissapointment, despite its over $1500 price tag and status as one of the "premier" products. If your hunting involves primarily going from place to place where you stay in a comfortable lodge and you have a guide who shows you the animals and you just look at what he points out (meaning he does most of the actual hunting,) this may be a decent choice of binocular. However, if you do a lot of hunting where you actually have to do the work of finding and evaluating the animals yourself, you will likely be better off with the full-size glass. There is a cute little saying that goes around in hunting circles a lot, "Optics cost nothing and they weigh nothing." There is a lot of truth to this statement. Interestingly, I have never known, nor have I ever been made aware of a single hunting guide who used anything but full sized binoculars in plying their trade.

If you like this class of binocular, then they are available for you. Research them to find the models will be the best for your needs, buy the best one that you can and enjoy. But, the suggestion that they are the ultimate solution for all people engaged in any particular activity (hunting, in the case of this article) is simply ludicrous.

Sorry Lucznik,
It wasn't my intention to insult your intelligence by posting the aforsaid article. You will have to write the author about that. I was merely trying to point out the advantages the smaller format has when compared with larger binoculars. Especially when you have to carry them around all day on rough terrain with other gear, as the author emphasized.

Have a nice day,
Bob

Isn't it interesting that we have birders touting 15X56 bins and hunters proclaiming 8X32 is all you need, even in the vast spaces of the American West.

ceasar said:

Sorry Lucznik,
It wasn't my intention to insult your intelligence by posting the aforsaid article. You will have to write the author about that. I was merely trying to point out the advantages the smaller format has when compared with larger binoculars. Especially when you have to carry them around all day on rough terrain with other gear, as the author emphasized.

Have a nice day,
Bob

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Truly, no offense was taken. I apologize if I made it seem that way.

(In truth it would be difficult for you to insult what I don't really have )

No apology needed Lucznik. Think nothing of it.

I think John Traynor might have stumbled on to something like the author of the article in question did. Are you acquainted with Deutsche Optik in Yerington, NV. www.deutscheoptik.com. They specialize in used and refurbished WWII military binoculars. A review shows that most of the bins in use by the army's of the world are either 6 x 30 IF or 8 x 30 IF porros. IF because they can be waterproofed easier than Central Focus porros and also because their "targets" are large and stationary. Not unlike hunting, wouldn't you say? The current catalog features UNISSUED Swiss army Leica 8 x 30 IF's that look uncannily like the Nikon 8 x 30 EII's with their oversize prism housings. Frankly, I don't see why you couldn't take these on a hunt out west where you would keep them prefocused at infinity. They wouldn't be good for the close hunting we have here in the east, but there is no reason they wouldn't be adequate in the wide open spaces out west.

If anybody wants a new Leica Porro Bin for only $529.00 check out the above web site.

Bob

Yes, I have seen Deutche Optik in the past. I think that the fact that the militaries of the world have traditionally used the 6 or 8x30 format to look at their large, stationary targets is a good example of the guided type of hunting I mentioned before where the guide is simply showing the "hunter" what to look at and then also makes the decision as to whether or not the hunter should take the animal. Unfortunately too many of the writers of articles for hunting publications are primarily involved in this kind of hunting so their views on what makes for good hunting optics tend to be rather skewed from the experience of most real world hunters who can't afford to spend thousands of dollars at a time on a guide and so must learn to do everything themselves. Such real world hunters are very much better off with a quality full size binocular. Very few military applications have the soldier sitting on a hillside glassing for hours on end for their target and then trying to judge the "trophy quality" of that target once it is sighted. They mostly look at stuff that they already know is there (buildings, crowds of people, tanks, camps, etc.) In the case of the "checkpoint charlie" model offered by Deutche Optik, the soldier would be dealing with a situation where the exact distances were alway the same and thus always known. Setting a binocular's focus only once for such a situation would be not only possible but, very useful. I noticed with some interest that in Iraq, some US troops are now being issued mini Steiner binoculars (presumably for their easy portability and for the fact that the vast majority of their use will be during daylight hours) which are all of CF design.

A lot of people seem to think that the IF binocular would be good for hunting here in the west. All I can tell you in this regard is the experience I have had with my uncle. He owns a 10x40 IF Leupold binocular that he has used for a long time as his primary hunting binocular. A few years back I bought a Pentax DCF WP which is, of course of CF design. Since that time, there has not been a single occasion when we have hunted together where he has not commented on how much more user friendly my binocular is than his. Optically they are very similar but, the ease of being able to quickly switch from very distant viewing to very close viewing and to be able to alter the focus in brushy terrain to pick out detail of what might lie beyond the brush give the CF binocular a definite edge. Often we look for deer and elk at distances ranging from right in front of us to 5+ miles away, all from the same vantage point. The IF binocular's focus cannot handle this extreme change in distance without having to be readjusted at least once (usually more than that) which is a big hassle as both barrels have to be adjusted individually. My binocular only requires a turn of the focus knob. Besides, all CF binoculars include a diopter adjustment so that each eye is still being treated as an individual. Before I bought my Pentax, I had always liked my uncle's binocular (and so did he.) In fact I even offered to buy it from him but, he wouldn't sell it. A while back we had a good laugh together as he told me he wished he had accepted my offer and I responded that I was really glad he had refused. I'm sure there are people who like the IF design but, I for one am convinced that they are an inferior system.

In the ancient past, before phase coated roof prism binoculars, the IF Porro, was the most reliable binocular with good resolution for foul weather and rough treatment. It is still favored by mariners.

Happy bird watching,
Arthur :brains:

IF...scratches head...!!...individual focus!

ceasar said:

No apology needed Lucznik. Think nothing of it.

I think John Traynor might have stumbled on to something like the author of the article in question did. Are you acquainted with Deutsche Optik in Yerington, NV. www.deutscheoptik.com. They specialize in used and refurbished WWII military binoculars. A review shows that most of the bins in use by the army's of the world are either 6 x 30 IF or 8 x 30 IF porros. IF because they can be waterproofed easier than Central Focus porros and also because their "targets" are large and stationary. Not unlike hunting, wouldn't you say? The current catalog features UNISSUED Swiss army Leica 8 x 30 IF's that look uncannily like the Nikon 8 x 30 EII's with their oversize prism housings. Frankly, I don't see why you couldn't take these on a hunt out west where you would keep them prefocused at infinity. They wouldn't be good for the close hunting we have here in the east, but there is no reason they wouldn't be adequate in the wide open spaces out west.

If anybody wants a new Leica Porro Bin for only $529.00 check out the above web site.

Bob

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Bob,

These "Leica" 8x30's are not made by Leica Camera AG, but by the independent Leica company that used to be known as Kern. I tried a pair. They are optically identical to the old Kern 8x30 Swiss Army binocular, except that the optics have been ruined by the addition of internal laser filters which can't be removed. The laser filters greatly reduce light transmission and give the color transmission a strong blue tint. They're beautiful and unique little binoculars, but sadly not good for general use. The earliest examples of this body design were made in the 80's and still carried the Kern name. Those might not have the laser filters.

Henry