[FrankD]

Originally Posted by denco@comcast.n

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.

[Steve C]

Originally Posted by denco@comcast.n

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.

[Kammerdiner]

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

[etudiant]

Originally Posted by Kammerdiner

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.

[FrankD]

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.

[elkcub]

Originally Posted by henry link

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

[denco@comcast.n]

Originally Posted by Kammerdiner

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/...8x32-binocular

[denco@comcast.n]

Originally Posted by elkcub

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.

[Steve C]

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.

[ceasar]

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

[denco@comcast.n]

Originally Posted by ceasar

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

If you can on a SWA that works for me because I do that anyway.

[Steve C]

Originally Posted by ceasar

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 seethe edges through the corners of my eyes.

Bob

I posted this above but I will try again. With that kind of field, if you try and look directly at the edge, say to the left, you will get blackout with your right eye. If you force the issue when you get there, you will see two edges

[FrankD]

Originally Posted by Steve C

I posted this above but I will try again. With that kind of field, if you try and look directly at the edge, say to the left, you will get blackout with your right eye. If you force the issue when you get there, you will see two edges

I understand what Steve is referring to but want to offer some clarification. I think this is going to depend on the model of EWA we are referring to as well as our individual facial dimensions. I have run into Steve's issue with several models. Others I don't have that issue. I can easily roll my eyes around the entire view and see the field stop quite clearly....and I don't get blackouts in either eye. For me it depends on the ocular design and how far it is recessed from the edge of the "eyecup". I put eyecup in quotes simply because, in somce cases, there isn't an eyecup as I have removed it. Not sure what I want to call the eyepiece "column"...the metal tube that the eocular lens actually is mounted into.

It is also going to vary based on the listed field of view. We are throwing around the term "extra wide angle" or "super wide angle" pretty loosely. I guess for the sake of discussion, and assuming a 7x35 model, that anything with 10 degrees or wider would be a safe bet. That would rule out the Nikon WF/Gold Sentinels and a few others. With many 10 and 10.5 degree models I don't have problems seeing the field stops. With some 11 degree models I can see the field stops clearly but others I cannot. Once you get above that then it is difficult to see the edges...at least for what I have on hand and for my facial dimensions.

[denco@comcast.n]

Originally Posted by FrankD

I understand what Steve is referring to but want to offer some clarification. I think this is going to depend on the model of EWA we are referring to as well as our individual facial dimensions. I have run into Steve's issue with several models. Others I don't have that issue. I can easily roll my eyes around the entire view and see the field stop quite clearly....and I don't get blackouts in either eye. For me it depends on the ocular design and how far it is recessed from the edge of the "eyecup". I put eyecup in quotes simply because, in somce cases, there isn't an eyecup as I have removed it. Not sure what I want to call the eyepiece "column"...the metal tube that the eocular lens actually is mounted into.

It is also going to vary based on the listed field of view. We are throwing around the term "extra wide angle" or "super wide angle" pretty loosely. I guess for the sake of discussion, and assuming a 7x35 model, that anything with 10 degrees or wider would be a safe bet. That would rule out the Nikon WF/Gold Sentinels and a few others. With many 10 and 10.5 degree models I don't have problems seeing the field stops. With some 11 degree models I can see the field stops clearly but others I cannot. Once you get above that then it is difficult to see the edges...at least for what I have on hand and for my facial dimensions.

So you don't see any edge so it is like your eye with normal vision. You are not limited by a place where the field just stops it just goes off into infinity. Interesting.

[Steve C]

Originally Posted by FrankD

It is also going to vary based on the listed field of view. We are throwing around the term "extra wide angle" or "super wide angle" pretty loosely. I guess for the sake of discussion, and assuming a 7x35 model, that anything with 10 degrees or wider would be a safe bet. That would rule out the Nikon WF/Gold Sentinels and a few others. With many 10 and 10.5 degree models I don't have problems seeing the field stops. With some 11 degree models I can see the field stops clearly but others I cannot. Once you get above that then it is difficult to see the edges...at least for what I have on hand and for my facial dimensions.

That is where it is for me too. If you want to see how your particular eyes will react to the presence of the extra wide field edge effect, than I think you need 11* @ 7x. I have a Swift Nighthawk 8x40 @ 9.5* which shows the same thing. Those afov's are 76 and 77*. I have a Sans & Streriffe Viking 8x30 @ 10* (80*) but it is not so illustrative of this fov effect. It has a little eye relief and I get best views about 3-4 mm off the ocular. Be aware if you are looking for something to stick to that level I think. Wide angle or extra wide angle was applied for 9.5* clear out to 13*.

I really get the feeling sometimes that some people are bound and determined to be bothered by the edge effect. Maybe some of them will see the edge at 100* afov. Maybe they can see their left ear with their right eye too. And again, the edge does not disappear, it moves out into (more or less) the periphery of the view, where its presence is lessened a great deal, but not removed.

I'm going to address Henry's comments on actual vs stated fov too. Just need to set up and take some notes. It is kind of embarrassing I have not done that already.

The less eye relief the greater the wide angle effect is. Like Frank, on all of the best binoculars to illustrate this I too, gave removed the eye cup. Some of the blackout may well be physical contact of the eye lid and the ocular lens. But IF you back off, the view shrinks.

Dennis,

Yes the effect is a lot (not completely) like having your normal vision magnified edge to edge, in the sense of a lesened awareness of the presence of the edge of the field.

[etudiant]

Originally Posted by Steve C

Yes the effect is a lot (not completely) like having your normal vision magnified edge to edge, in the sense of a lesened awareness of the presence of the edge of the field.

It seems as though the use of glasses pretty much precludes this perception of magnified normal vision.
Certainly extra wide angle binoculars have never worked for me, perhaps because my needing to correct 300/400 vision ensures that there is never enough eye relief.
That said, the old Zeiss 7x42 did give me more of a 'picture window' effect than any other glass I've ever owned. It would be wonderful to get it in a higher power glass.

[elkcub]

Originally Posted by etudiant

...
That said, the old Zeiss 7x42 did give me more of a 'picture window' effect than any other glass I've ever owned. It would be wonderful to get it in a higher power glass.

I think I know what you're talking about. Take a look at: http://www.birdforum.net/showthread....69#post2326669

So far as I'm concerned the new 8x42 SLC HD meets the requirement splendidly with an 18.5mm eye relief. I've put aside my 7x42 BGATP with its picture window for the duration. Unfortunately, Cameraland seems to be out of their salesman's samples, but the binoculars are available for about $1900. Expensive, yes. Worth it, ... YES!

The SVs are another way to go.

Ed

[brocknroller]

Back to the topic of why the need for an EWF birding bin, which Frank touched upon in post #51. Here are some specific examples.

I have a suet feeder in my backyard, and it gets very popular in the winter - sparrows, woodpeckers, nuthatches, chickadees, Blue Jays, and even the occasional squirrel all vying for position to get at the peanut butter flavored fatty concoction.

Once while I was sitting in the backyard on a cool but not cold winter's day, I caught this interaction btwn sparrows and a nuthatch.

Three sparrows were vying for a position on the suet feeder, with one waiting on a nearby branch and two on the feeder. Here comes a nuthatch creeping down the trunk of the tree. Seeing the sparrows, he spreads his wings and flaps them, as if it to say, get lost, it's my turn. They ignored him, so he came closer and did the same display and also made some noise. The most aggressive sparrow on the feeder made some nose too and did a threatening lunge at the nuthatch to get in the last word, but then three sparrows scattered and the nuthatch gained control of the suet.

With the 8.8* FOV 8x30 EII, I could watch the nuthatch and the sparrows reaction including the sparrow on the branch all in one view. With the 6.5* Swift 8x44 ED, I had to keep going back and forth from nuthatch to suet feeder to sparrow on the branch to see the whole thing unfold.

Another example. I walking to the park and had the 8x EII with me. I spotted a hawk circling about a block or two away on the other side of the road.

Starlings and mourning doves by the dozen were perched on power lines in the foreground.

As the hawk came closer he began to dive toward the power lines and both the starlings and morning doves took off.

They began swarming, each species to his own, but as the hawk came closer, the starlings and mourning doves joined up, turned and twisted in formation like Farnborough Air Show acrobatics.

Anyone who has watched flocks of starlings and mourning doves fly, knows their flight pattern is quite different - yet when joined together, they adopted the same pattern.

I thought that was an amazing example of cooperation between species. The hawk who was now visible in the same FOV was perplexed, befuddled, and desperately trying to find a straggler, but no dice. After a couple approaches, which were meet with evasive maneuvers, he gave up and flew away.

I caught the entire action in one FOV w/out having to toggle back and forth between the front and back of the swarm and the hawk. This could never happen with a Monarch or Pentax 8x43 ED and other bins with moderate FsOV.

On another day, I watched a couple flocks of starlings join forces at another location to avoid a hawk. They would fly around and join up and then head for a tree. Stay there for a while until someone gave the signal a
nd they'd swarm again and lit down in another tree. Saw this action in the 9* 7x36 ED2.

So, yes, if you simply want to ID a species, you don't need a EWF or even a WF bin, a Monarch or Pentax 8x43 will do fine. But if you want to study bird interactions and watch birds flying in formation and study flock behavior, having a 9* FOV really helps.

Brock

[elkcub]

Brock,

The 804ED Audubon has a FOV = 430', which computes to 8.2º. It has an apparent field of 69.75 degree, which is slightly smaller than the 70.4 degrees of the E2. They both round to 70 degrees, and in effect are equally wide. Real fields of 8.8 vs. 8.2 also aren't all that different.

In any event, the property you're describing relates to the real field and could be accomplished with an undistinguished 6x instrument that most people would consider narrow, e.g., 6 x 9º (real) = 54º (apparent).

Ed

[denco@comcast.n]

Originally Posted by elkcub

Brock,

The 804ED Audubon has a FOV = 430', which computes to 8.2º. It has an apparent field of 69.75 degree, which is slightly smaller than the 70.4 degrees of the E2. They both round to 70 degrees, and in effect are equally wide. Real fields of 8.8 vs. 8.2 also aren't all that different.

In any event, the property you're describing relates to the real field and could be accomplished with an undistinguished 6x instrument that most people would consider narrow, e.g., 6 x 9º (real) = 54º (apparent).

Ed

"Real fields of 8.8 vs. 8.2 also aren't all that different."

I don't know about that! I see a signifigant difference. For each 20' of FOV I see a difference.

[denco@comcast.n]

Originally Posted by brocknroller

Back to the topic of why the need for an EWF birding bin, which Frank touched upon in post #51. Here are some specific examples.

I have a suet feeder in my backyard, and it gets very popular in the winter - sparrows, woodpeckers, nuthatches, chickadees, Blue Jays, and even the occasional squirrel all vying for position to get at the peanut butter flavored fatty concoction.

Once while I was sitting in the backyard on a cool but not cold winter's day, I caught this interaction btwn sparrows and a nuthatch.

Three sparrows were vying for a position on the suet feeder, with one waiting on a nearby branch and two on the feeder. Here comes a nuthatch creeping down the trunk of the tree. Seeing the sparrows, he spreads his wings and flaps them, as if it to say, get lost, it's my turn. They ignored him, so he came closer and did the same display and also made some noise. The most aggressive sparrow on the feeder made some nose too and did a threatening lunge at the nuthatch to get in the last word, but then three sparrows scattered and the nuthatch gained control of the suet.

With the 8.8* FOV 8x30 EII, I could watch the nuthatch and the sparrows reaction including the sparrow on the branch all in one view. With the 6.5* Swift 8x44 ED, I had to keep going back and forth from nuthatch to suet feeder to sparrow on the branch to see the whole thing unfold.

Another example. I walking to the park and had the 8x EII with me. I spotted a hawk circling about a block or two away on the other side of the road.

Starlings and mourning doves by the dozen were perched on power lines in the foreground.

As the hawk came closer he began to dive toward the power lines and both the starlings and morning doves took off.

They began swarming, each species to his own, but as the hawk came closer, the starlings and mourning doves joined up, turned and twisted in formation like Farnborough Air Show acrobatics.

Anyone who has watched flocks of starlings and mourning doves fly, knows their flight pattern is quite different - yet when joined together, they adopted the same pattern.

I thought that was an amazing example of cooperation between species. The hawk who was now visible in the same FOV was perplexed, befuddled, and desperately trying to find a straggler, but no dice. After a couple approaches, which were meet with evasive maneuvers, he gave up and flew away.

I caught the entire action in one FOV w/out having to toggle back and forth between the front and back of the swarm and the hawk. This could never happen with a Monarch or Pentax 8x43 ED and other bins with moderate FsOV.

On another day, I watched a couple flocks of starlings join forces at another location to avoid a hawk. They would fly around and join up and then head for a tree. Stay there for a while until someone gave the signal a
nd they'd swarm again and lit down in another tree. Saw this action in the 9* 7x36 ED2.

So, yes, if you simply want to ID a species, you don't need a EWF or even a WF bin, a Monarch or Pentax 8x43 will do fine. But if you want to study bird interactions and watch birds flying in formation and study flock behavior, having a 9* FOV really helps.

Brock

Good point! Brock. Exactly my feelings. So many times you are not looking at just one bird but several interacting and that big FOV of 462 feet is really helpful with that EII. 9 degree FOV and above is really nice. I am going to try the new Vortex Talon 8x32 with the 9 degree FOV @477 feet. That's 15 feet more than the EII. If the edges are pretty sharp it should be quite good. Probably not as good optically as the EII.

[vop]

Originally Posted by Pileatus

Re: Wide FOV

When you have a "huge" field of view with SOFT edges you end up with a lot of off-center blur, constant refocus and/or constant movement to maintain focus. Most, if not all, of the mentioned "wide-field" bins have soft edges!
I used a Leica 7X42 with a 420' real FOV for many years and I never enjoyed its "field of view" as much as my 8X32 SE with a real field of 393'. The Leica was dead sharp in the centerfield, but off-center it suffered from soft edges and it was often a serious distraction.

Swarovski nailed the problem: combine super sharp edges with a 399' FOV and the experience will be totally captivating. They proved there's simply no need for a larger FOV, even in very close quarters.

It's really good you can be happy!

Now what about those who can't because there aren't any extra wide angle alphas? Soft edges or not...

[denco@comcast.n]

Originally Posted by vop

It's really good you can be happy!

Now what about those who can't because there aren't any extra wide angle alphas? Soft edges or not...

"Swarovski nailed the problem: combine super sharp edges with a 399' FOV and the experience will be totally captivating. They proved there's simply no need for a larger FOV, even in very close quarters"

You don't think an SV view with a 500 foot FOV would be cool? I do. I don't think you would want to go back to 400 feet.

[black crow]

What happened to 600'?

[denco@comcast.n]

Originally Posted by black crow

What happened to 600'?

Most of the experts seem to think there is not an eyepiece available for a binocular that would give you a 600' FOV with 8x magnification so I have lowered my dream FOV to something that is within reason and could be accomplished. I'll try the Vortex Talon 8x32 when it comes out but I think the edges are going to be too soft for me. We will see. Does anybody know of a roof prism with a 500' FOV and pretty sharp edges.