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Why can' they make an alpha binocular with a 600 foot FOV and sharp edges? (4 Viewers)

Nice story Steve. I am jealous of your birding location. All those different species in one area . Wow! I agree proper technique is important. I still think it is pretty nice to have a big wide FOV especially on birds in flight because you can follow them easier and keep them in your FOV easier. Too me it is cool to see the bird framed in a big wide FOV with the surrounding scenery also.

Well, I did have an 11.5* (604') Tasco International 400 7x35 with darn nice optics as one of the binoculars in my possession. Not alpha, but yes it was impressive. ;)

Was a nice 60* F day today, but we had other things to do, so my original intention to go back today got thwarted. I have time the next couple of days, but the weather does not look too good.
 
Vop. I think you did graduate from the University. Excellent comment and exactly how I feel. I think once birders got used to a 500 to 600 feet FOV with sharp edges they would not want to go back to 400 feet. Kind of as you said like going from a 50 inch big screen to a 30 inch. I don't buy the comment about only newbies needing a big FOV. Most anybody would enjoy seeing more in a larger FOV. You can take in more information and it makes the view more interesting and likelike and less like looking down a tunnel in my opinion. Just like going to IMAX. Look at all the birders that like the 8x30 EII and it is all about a big FOV as we know.

Actually I dropped out... Peace brother! :hippy:
 
Kammerdiner,

I see how your birding goes: 1. There's a bird in sight. 2. You aim your binoculars on the bird.
Now suppose there's no bird in sight. Because there's only a call or a song. Or because it's beyond your eyes' reach. Or...

Renze

Actually I do a lot of my birding by ear, at least to find them. But unless you are really gifted, pinpointing birds by ear, in the woods anyway, ain't easy. My ears always tell me the bird is lower than it actually is. I can compensate, but it still ain't easy. Maybe some people have bat ears or something, but I don't. So rather than just wandering around staring at the trees with binoculars, I generally wait till I see something. Once I see it, the bins are up. FOV is pretty much a non-issue at that point, assuming you know the bins.

In more open habitats, well, there's one tree over there and there's a bird in it. Have a look. FOV won't help much then either, will it?

If you're looking for hawks, etc. far enough away that you can't even see them without binoculars, I still think FOV is probably not that big a deal. You'll find them soon enough. You're just scanning anyway.

As for magnification I just can't get into 7x. 8-8.5x has always been my favorite.

Mark
 
Actually I do a lot of my birding by ear, at least to find them. But unless you are really gifted, pinpointing birds by ear, in the woods anyway, ain't easy. My ears always tell me the bird is lower than it actually is. I can compensate, but it still ain't easy. Maybe some people have bat ears or something, but I don't. So rather than just wandering around staring at the trees with binoculars, I generally wait till I see something. Once I see it, the bins are up. FOV is pretty much a non-issue at that point, assuming you know the bins.

In more open habitats, well, there's one tree over there and there's a bird in it. Have a look. FOV won't help much then either, will it?

If you're looking for hawks, etc. far enough away that you can't even see them without binoculars, I still think FOV is probably not that big a deal. You'll find them soon enough. You're just scanning anyway.

As for magnification I just can't get into 7x. 8-8.5x has always been my favorite.

Mark

I agree about magnification. 8x is my favorite also. It takes a little learning but spotting birds by hearing them works good once you learn how to do it. My guide in Costa Rica taught me how to do this. He knew exactly by the sound of the bird it's species and then he knew based on that information WHERE to look for them in the jungle. But of course local knowledge and experience always helps! He knew where the birds usually hung out.
 
Well, I did have an 11.5* (604') Tasco International 400 7x35 with darn nice optics as one of the binoculars in my possession. Not alpha, but yes it was impressive. ;)

Was a nice 60* F day today, but we had other things to do, so my original intention to go back today got thwarted. I have time the next couple of days, but the weather does not look too good.

I am going to have to buy a pair of these SWA vintage binoculars. What ones do you recommend as the best. The Nikon 7x35 porro's WA 1980 vintage or are the Tasco's better? I'd like something with a 500+ FOV.
 
I feel pretty certain that most of the posters on this thread intend to be discussing a class of super-wider angle binoculars with apparent fields of around 80 degrees. However, the casual use of real field numbers, without any reference to magnification, is obviously causing some confusion. For instance the thread title refers only to a 600’ FOV with no reference to magnification. A 5x binocular with a 600 ft@1000yds FOV wouldn’t even qualify as “wide angle”, much less “super wide angle”. On the other hand, a 10x binocular with a 600’ FOV would have an AFOV in excess of 110 degrees, wider than any commercially available eyepiece. Some of the binoculars that have been mentioned (like the Binon 5x32) have spectacular sounding real fields, but are just “normal” wide angle binoculars once you take the magnification into account. I think it also might be interesting to actually measure the FOV for some of these old super-wides. I wouldn’t be surprised to find some exaggeration in the specs.

Anyway, if the idea is to discuss binoculars with AFOV about equal to 82 degree Naglers you need to do a little math. First, divide the FOV in ft@1000yds by 52.5. That will give you the real FOV in degrees. Then multiply that by the magnification for an approximation of the apparent field. In the real world the “true” apparent field is almost always different from what’s predicted by this method, but no mathematical formula will accurately derive apparent field from real field (or vice versa) unless a value can be assigned to the varying amounts of pincushion distortion in each binocular. Since the value of the pincushion is generally not known an approximation is the best you can do without making a direct measurement.
 
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Mark,

Sounds like our birding styles are similar, even down to thinking that singing birds are lower than they really are. I also agree with you that super wide angle binoculars are not particularly useful for birding. I'm just not willing to deal with the unpleasant aberrations and distortions that come with 80 degree fields, even with Nagler eyepieces (really especially with the huge pincushion distortion of Nagler eyepieces). From long experience with many binoculars I know that I'm happy enough once the AFOV reaches about 60 degrees and I don't pine for anything over about 65-70 degrees.

Henry
 
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I agree about magnification. 8x is my favorite also. It takes a little learning but spotting birds by hearing them works good once you learn how to do it. My guide in Costa Rica taught me how to do this. He knew exactly by the sound of the bird it's species and then he knew based on that information WHERE to look for them in the jungle. But of course local knowledge and experience always helps! He knew where the birds usually hung out.

Absolutely. You don't look for a singing Ovenbird, for instance, up in the treetops. But good luck trying to find that Blackpoll warbler by sound alone!

I birded ten years with an 8x42 that only had 330'. Maybe that's why I don't crave ultra-wide bins. I wouldn't go back, but 400-425' seems just about right. I've used the Zen 7x36 at 477' and for me the extra FOV was not really useful.

Henry, interesting that you hear birds lower too. My wife, who can't remember birdsongs to save her life, can nonetheless locate them better than I. Ear shape, maybe? Or something in the brain?
 
I am going to have to buy a pair of these SWA vintage binoculars. What ones do you recommend as the best. The Nikon 7x35 porro's WA 1980 vintage or are the Tasco's better? I'd like something with a 500+ FOV.

Dennis,

If you are serious then send me a PM and we can discuss some models.

;)

Mark,

Again, I cannot really find fault with your reasoning. Your specific example about the bird in a lone tree illustrates your point quite well. However, what it does not take into account is the experience generated while watching the bird. For me personally I find that having as much in view around the bird, as well as the bird itself, is preferrable.

To play devil's advocate a bit, what happens when another bird, several feet above the first bird, flies "into the picture". With a wide angle model you may pick up the second bird whereas you wouldn't with one that had a narrower field of view.

Of course, we are splitting some pretty fine hairs here. I always enjoy when someone points out the actual differences in fields of view at typical birding distances. Our discussions are focused on the differences of field of view at 1000 yards. The question should actually be what the differences are at typical birding distances....20-100 feet? Probably not as significant as one might think. Your Swarovision is listed as having a spec of 399 feet IIRC. Some of these EWA 7x35s are about 200 feet wider. So basically we are looking at about a 2 to 3 ratio. So, just hypothetically, if your Swaro can see 20 feet at a given distance then the EWA should be able to see 30.

Would that be enough to make a difference in certain situations? Yes, it would. In others it probably would not.

Again though you do bring up an interesting point. If the entire purpose of using a binocular is to find a specific object and center it in the field of view then what good is edge performance? Who would care about sharp edges?

My answer to that question is that there is more to a binocular's performance than just how it represents an object in the center of the field of view. I don't think many folks would disagree with this. The question then becomes...if edge performance is important to the overall viewing experience then why not the width of the field of view as well?

Just something to think about.
 
I am going to have to buy a pair of these SWA vintage binoculars. What ones do you recommend as the best. The Nikon 7x35 porro's WA 1980 vintage or are the Tasco's better? I'd like something with a 500+ FOV.

I reccommend you take Frank up on his offer.

Here is what I see with the increase in fov. At about 9*, the edge of the fov starts to become hard to see. At 10*, the double edge edge begins to assert itself, and each half degree upwards makes the edge even harder. By the time I reach 11*, there is only some vauge peripheral awareness of the edge and actually looking at the edge is not possible.

I was going to suggest looking at Frank's flickr page. I don't have one up yet but it will look a lot like Frank's. With the old japanese porros there are more similarities than differences. They tend to look like the same design with maybe different armor, a different badge, and different J-B codes.

The Tascos are a good place to start. look at either the model 116 or the model 400 International, I like the latter better. They are solid, substantial, double handfuls of binocular with decent optics. Not alpha, they are single coated and have Bk-7 prisms. Still they perform surprisingly well.

Even if you get one from Frank, get two. Frank and I have a history of buying, selling, and trading back and forth, but the freight monkeys are in full raging glory lately and I have barely been at the level of recieving 50% of what I order coming out of the box usable. Even Frank's properly packaged stuff has not been immune. I suspect the problem is in Portland, Oregon as that is the one common point where binoculars from both coasts and the heartland all have to meet before they get sent here to Klamath Falls.

If you want wide field you need more than 500' I think (keep in mind the above fov is my 7x stuff). You are also out of luck if you wear glasses with binoculars. None of Nikons earlier porros have much above 9.3* (if any). Great optics, but not true extra WA. Some Nikon (notably the Naturalist II)have great optics but body manufacturing was farmed out to Toys-R-Us.

Off the bay auctions should see you find one shipped for about $30. I just this morning bagged what looks like a pristine Wards 11.8* (620') 7x35 with free shipping for $29.99. In Arizona, so It should not take forever to get here. There are few on the block with no bids that have current prices of $5-10.
 
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Good points, Frank. OK, so I'll go for a wider view, but only if it's sharp. The SV kinda spoils a person that way. And it will need good eye relief because I really dislike mashing binoculars against my face/glasses. I'm guessing most/all of those older EWA's have very limited eye relief, yes?

I think Vortex is coming out with an 8x32 Viper with 477' some time this year. Could be interesting.

All in all, I'd still put FOV below other priorities, though. I just never really find myself saying, Dang, if I just had a wider view.

Mark
 
Good points, Frank. OK, so I'll go for a wider view, but only if it's sharp. The SV kinda spoils a person that way. And it will need good eye relief because I really dislike mashing binoculars against my face/glasses. I'm guessing most/all of those older EWA's have very limited eye relief, yes?

I think Vortex is coming out with an 8x32 Viper with 477' some time this year. Could be interesting.

All in all, I'd still put FOV below other priorities, though. I just never really find myself saying, Dang, if I just had a wider view.

Mark

Very interesting perspective, because my preference would be for a very wide field, even at the price of distortion, just to pick up the peripheral activity.
As long as the center image is good, soft perimeters would be fine with me.
Certainly the normal action is to center the glass on the object being viewed,
rather than scanning across the binocular image.
The wide angle Vortex sounds interesting, provided it has glasses friendly eye relief.
 
Mark,

Apparent sharpness isn't an issue with the classic porros. All of my "keepers" offer surprising levels of apparent sharpness. The size of the sweet spot varies depending on model with the average being something like 60-70% apparent. Some models are certainly better than that and one or two approach 90-95%.

Almost all of them have very short eye relief. I say that with one caveat. It isn't that eye relief is short. It is more of a matter of usable eye relief being short. Many of these models either have the ocular surface recessed into the eyecup a fair amount or the width of the eyecup prevents you from getting your eyes close enough to the ocular surface. I ran into this problem with one particular 7x50 model. I have modified it a bit by completely removing the eyecup. Now the ocular surface is close enough to the rim of the eyecup shaft (sans eyecup) plus the eyepiece barrels are narrower so I can get them past my nose and more into my eye sockets. I can now see the full 525 feet with this 7x50....and it is an amazing view. Very large sweet spot and tons of room for my eye to roam around the image because of the 7+mm exit pupil.

I do look forward to trying out the new Vortex. My only "beef" with it is nothing that can be remedied. It only has a 4 mm exit pupil. ;)

I don't blame you for not feeling like you need more field of view. The apparent field on the Swaro 8.5 is close to 65 degrees. That is certainly generous for a modern roof. I never felt cramped with roofs in the 60-65 range. But these older porros are an entirely different animal. Not only is the field of view wider but they are tack sharp and have excellent apparent depth of field. Plus they are made very well. Consider many of them have been in use for 60 years and they still perform exceptionally well. I digressed a bit though as we were talking strictly field of view and not necessarily porro versus roof.
 
Mark,

Sounds like our birding styles are similar, even down to thinking that singing birds are lower than they really are. I also agree with you that super wide angle binoculars are not particularly useful for birding. I'm just not willing to deal with the unpleasant aberrations and distortions that come with 80 degree fields, even with Nagler eyepieces (really especially with the huge pincushion distortion of Nagler eyepieces). From long experience with many binoculars I know that I'm happy enough once the AFOV reaches about 60 degrees and I don't pine for anything over about 65-70 degrees.

Henry

Hi Henry,

I concur with your conclusions, and also the earlier admonition about the apparent field being the correct reference for "wideness." I would also note that there is an inevitable tendency to mix birding with astronomy applications, which are vastly different in requirements.

For birding binoculars my thinking is based more on human engineering analysis than optical engineering. To me it's axiomatic that the best visual instrument should be the most compatible with the way the human body works, and not force behaviors that are uncomfortable or unnatural.

This now famous 1976 diagram hasn't changed over many revisions of MIL-STD-1472 concerning Human Engineering Design Criteria. I don't know the underlying research that led to it, but it has been widely accepted for equipment design throughout the world. Of course, to be relevant here it has to be interpreted in a viewing situation using binoculars.

Here is now the authors describe the way eye-head movements work. I'll just quote it:
Discussion. Focal vision is the central 30° of the visual field, pictured as the shaded area in the top panel of the Exhibit 5.1.2.10, (along with the range of eye movements with the head stationary). This is the area that people use to look at objects in the world, moving their eyes as needed to bring images of the object on to the fovea, which is the area of highest acuity. When an object is outside of the focal area, a person will usually turn the head rather than simply move the eyes. The range of head rotation is illustrated in the second panel of Exhibit 5.1.2.10. The combined range of combined head and eye movement is illustrated in the third panel of Exhibit 5.1.2.10. By locating frequently used displays in the central 30° of visual field, the user is not required to move his or her head to bring the information into the focal area, presumably minimizing neck strain.
Now an important point about binoculars. With unaided vision the angular movement of the head and eyes trade off 1:1. One can either move the eyes x degrees to the left or right, or the head. The net result is that the image of an object can be centered on the fovea either way, or by a combination of head and eye movements so long as they sum to x degrees.

Using binoculars the situation is modified. Head motion still associates with object location, but eye movement associates with magnified retinal location. In other words, the image of a real object x degrees to the left or right can still be centered by head motion of x degrees, but it takes eye motion of M*x degrees to center the object's image using only the eyes. A consequence of magnification, therefore, is that the eye becomes (so to speak) M times less efficient for centering the images of real objects than the head.

The diagram shows that using eye rotation alone, optimum lateral movement is ±15º, with a maximum of ±35º. The ±15 degree region, I'm sure, corresponds to a zone of "reasonable" acuity. The outer region corresponds to a retinal projection area, or apparent field of view, of up to 70º —which by happy coincidence coincides with quality binoculars that are usually 60º — 70º.

It's obviously not a hard limit, but if the field edge is beyond a ±35º, eye muscles become progressively more fatigued, and for me that's unreasonable. It is also true, although unmentioned in this discussion, that eye rotation mechanically results in ray clipping at the point where the exit pupil meets the eye pupil, — about 3mm behind the cornea. The observer is also called upon to recenter the instrument, although this doesn't alleviate the clipping problem.

It could still be argued, of course, that there is an advantage in presenting a larger magnified field to: (a) increase the psychological sense of "presence," or (b) provide peripheral cues for guiding search movements. That may (or may not) be true, but such an increase in field comes at the expense of eye relief, which in my opinion is much more important. About 75% of the US population uses either spectacles or contact lenses. in addition, as recently discussed on other threads, both presence and peripheral cues are somewhat compensated for when glasses are used, because unmagnified peripheral images become available to the eye. Although opinions may differ about the value of this, my experience is that conventional eyecups invariably create tunnel vision, independent of the apparent field.

Anyway, that's how I see it.

Ed
 

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Good points, Frank. OK, so I'll go for a wider view, but only if it's sharp. The SV kinda spoils a person that way. And it will need good eye relief because I really dislike mashing binoculars against my face/glasses. I'm guessing most/all of those older EWA's have very limited eye relief, yes?

I think Vortex is coming out with an 8x32 Viper with 477' some time this year. Could be interesting.

All in all, I'd still put FOV below other priorities, though. I just never really find myself saying, Dang, if I just had a wider view.

Mark

The Vortex 8x32 with 477' sounds interesting. That is my favorite size and it would have modern coatings and still be a manageable size. That is interesting that the edge of the FOV dissappears on the really wide FOV binoculars. Most of the older WA porro's were 7x which I am not sure I am fond of never really liking the Zen Ray 7x36 that much. ER is a consideration too on the SWA.Here is a link to the Vortex Viper with 477 FOV.

http://www.vortexoptics.com/product/vortex-talon-hd-8x32-binocular
 
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Hi Henry,

I concur with your conclusions, and also the earlier admonition about the apparent field being the correct reference for "wideness." I would also note that there is an inevitable tendency to mix birding with astronomy applications, which are vastly different in requirements.

For birding binoculars my thinking is based more on human engineering analysis than optical engineering. To me it's axiomatic that the best visual instrument should be the most compatible with the way the human body works, and not force behaviors that are uncomfortable or unnatural.

This now famous 1976 diagram hasn't changed over many revisions of MIL-STD-1472 concerning Human Engineering Design Criteria. I don't know the underlying research that led to it, but it has been widely accepted for equipment design throughout the world. Of course, to be relevant here it has to be interpreted in a viewing situation using binoculars.

Here is now the authors describe the way eye-head movements work. I'll just quote it:

Now an important point about binoculars. With unaided vision the angular movement of the head and eyes trade off 1:1. One can either move the eyes x degrees to the left or right, or the head. The net result is that the image of an object can be centered on the fovea either way, or by a combination of head and eye movements so long as they sum to x degrees.

Using binoculars the situation is modified. Head motion still associates with object location, but eye movement associates with magnified retinal location. In other words, the image of a real object x degrees to the left or right can still be centered by head motion of x degrees, but it takes eye motion of M*x degrees to center the object's image using only the eyes. A consequence of magnification, therefore, is that the eye becomes (so to speak) M times less efficient for centering the images of real objects than the head.

The diagram shows that using eye rotation alone, optimum lateral movement is ±15º, with a maximum of ±35º. The ±15 degree region, I'm sure, corresponds to a zone of "reasonable" acuity. The outer region corresponds to a retinal projection area, or apparent field of view, of up to 70º —which by happy coincidence coincides with quality binoculars that are usually 60º — 70º.

It's obviously not a hard limit, but if the field edge is beyond a ±35º, eye muscles become progressively more fatigued, and for me that's unreasonable. It is also true, although unmentioned in this discussion, that eye rotation mechanically results in ray clipping at the point where the exit pupil meets the eye pupil, — about 3mm behind the cornea. The observer is also called upon to recenter the instrument, although this doesn't alleviate the clipping problem.

It could still be argued, of course, that there is an advantage in presenting a larger magnified field to: (a) increase the psychological sense of "presence," or (b) provide peripheral cues for guiding search movements. That may (or may not) be true, but such an increase in field comes at the expense of eye relief, which in my opinion is much more important. About 75% of the US population uses either spectacles or contact lenses. in addition, as recently discussed on other threads, both presence and peripheral cues are somewhat compensated for when glasses are used, because unmagnified peripheral images become available to the eye. Although opinions may differ about the value of this, my experience is that conventional eyecups invariably create tunnel vision, independent of the apparent field.

Anyway, that's how I see it.

Ed

Interesting theories but I still think a larger FOV still has advantages in birding if the detractions could be overcome optically. If you had a 500' FOV with sharp edges and good ER I think alot of birders would buy those binoculars over a 400' FOV with the same optics. I would like a 500' FOV with 8x magnification.
 
Dennis

To be clear, the edge does not disappear, it is quite obviously there. What happens is that it far enough out that you can't actually look directly at it. Get an EWA porro and you will see. EWA for this is say, 75* afov and up. There are lots of good 11* 7x35's for illustrating this.
 
I assume that you can roll your eyes side to side and see it. I do that routinely with modern "wide" field binoculars but can also see the edges through the corners of my eyes.

Bob
 
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