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FOV - beyond what value is too much? (1 Viewer)

Troubador

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Well Lee, as you should know from our previous copious personal emails, thats not true. That is exactly the kind of birding I do every day Im out. I birded 3 days a week this years migration (Sept to April), all of it over large tracts of open water. San Francisco Bay, I suspect qualifies, as one example, you could envision. As with glare that I dont see either, I rarely wish for more FOV in my EL 1042s. I have no problem tracking fast moving ducks, geese and raptors out there or zooming in on the occasional Anna's flitting about in bushes a few feet away. In what some may see as my not so humble experience, if folks would stop shopping for binos, comparing this one with that one, and just go use them... hard, these things become doable.
For sure it is possible to have enjoyable and educational wildlife observing with most binoculars whether they have large fields of view or not, nor do they have to be the most expensive top-of-the-line models, and I am happy to note that you 'rarely' wish for more fov than your ELs. Nevertheless bigger fields of view do make many viewing situations easier. On a historical note, I am sure our friend Gijs van Ginkel would confirm that super-large fov is not a recent phenomenon and goes back many decades to the days when porros were the only choice.

Lee
 

Troubador

Moderator
Staff member
Supporter
Surely you jest! Take those published 1000 whatever FOVs that we love to wax on about, reduce them to practical birding distances and things are pretty underwhelming. No one who just bought the newest and bestest FOV'd bino wants to hear this, I get it. The makers are making it easier to compare? please. They're making their products look better so we'll buy them.
Those ways of expressing fields of view have been around for many, many decades and using this common method means folks can easily compare binoculars. You keep mentioning 'practical birding distances' as though all birding (indeed all nature observing) takes place at 100 yards or less, despite my having just provided plenty of examples of birding at far greater distances and despite you mentioning San Francisco Bay as the venue for observing by yourself.

Lee
 

wllmspd

Well-known member
As Lee notes, there have been super wides binoculars from back to at least the 1940s, I have some “recent” ones from the 1960s, nice, but a little heavy and a little short on the eye relief. FoV specs are like 0-60mph for cars… not everyone is flooring the gas at every set of lights. When you get upto 65degrees AFOV things are nice and open, more can be better, but you don’t feel overly constrained.

Peter
 

Troubador

Moderator
Staff member
Supporter
OK, well. I'm skeptical of birders getting much information at 1000 yards or meters. Maybe someone on a boat coming into a harbor and wanting to discern the channel via green or red buoys. But birds? Maybe California Condors. Most will reach for their spotting scopes long before that.

Here's the point some of us are trying to make, expressed in numbers

@1000 yds NL Pure 1042 = 399'
@1000 yds EL 1042 = 336'
399-336=63/336=19% (rounded up), greater for NL

@100 yds NL Pure 1042 = 39.9'
@100 yds EL 1042 = 33.6
Thats 6.3', (divide that by 2 as you get half on each side)

@50 yds NL Pure 1042 = 19.95'
@50 yds EL 1042 = 16.8'
A whopping 3.15'
Tom, you can be as skeptical as you like, go back to my post giving examples of long distance bino use. When you are familiar with the species that are in a location you don't need to be able to see the detail of their wing coverts or some other tiny detail. For example separating Golden Eagle from White-tailed Sea Eagle isn't too difficult at long distances, same with separating Razorbill from Guillemot, or Kittiwake from gulls. Scanning across mudflats at long distance you won't be able to separate species of Stints but you can tell a Stint from a Dunlin and Godwit from a Curlew and even a Whimbrel from a Curlew, and Ringed Plover from Dunlin.

Lee
 

Swedpat

Well-known member
In my opinion, after having all the NL's and SF's with their huge FOV's I think the sweet spot is about a 65 degree AFOV or about 8 degrees in an 8x or 6.5 degrees in a 10x. I firmly believe the wider FOV roof prism binoculars with their wide angle eyepieces are more prone to glare problems, like I had with the NL 8x42. I think this is the big reason Swarovski reduced the FOV on their NL 8x32 because they knew they had glare problems with the NL 8x42. Usually an 8x32 binocular in the same model line will have a bigger FOV not smaller. It seems like this problem is unique to roof prism binoculars because 9 degree porro prism binoculars like Nikon E2 8x30 are quite good at handling glare. You reach a point in FOV where you can't take the whole FOV in at once anyway. Yes, maybe you can catch a bird at the edge of the FOV, but is that really that useful when the important thing is the quality of the on-axis view once the bird is centered. I would rather have a quality 8 degree FOV than a 9 degree FOV with glare. I will take quality over quantity any day of the week. This could be part of the reason Zeiss went back to an 8 degree FOV on their new SFL, along with the fact that it probably has simpler and lighter eyepieces, and I am glad they did. I think it will be a relatively glare free, as well as lighter binocular because of it.

I wonder about the reason to that almost all 8x32 have wider FOV than 8x42 in same series.
And as you say NL Pure is an exception. But does the 8x32 have less glare than the 8x42?
One reason to that NL Pure 8x32 has narrower FOV than the 8x42 can also be that Swarovski chose not to sacrifice eye relief. I have not tried the 8x32 but if the ER is the same in practise, and not only on the paper, as 8x42 that surely is the reason.
 

Binocollector

Well-known member
Germany
I am a bit surprised somebody has not pointed this out. For example if a binocular has a liner FOV of 8*, each barrel is 8*. You don,t get 4* from each side. You get 8* from each side, just like we get 1x from our left eye and 1x from the right eye.
I literally had written the same but never sent the post as the discussion had moved on too fast to keep up (when I had checked the discussion to post my answer -- there were already new posts) and being a newbie on the forum and all, I didn't want to sound like a wise-cracking smartypants :D.
 

Troubador

Moderator
Staff member
Supporter
It is true that the eye doesn’t examine the whole field at once, our eyes can only really see small details at a small central point on the retina- this is why your eye has to move to read this text, even on a tiny cellphone. Our eyes do use the rest of our vision to pick up shapes or movement to key in on though, and this is where a large FOV is really useful.
Absolutely correct.

Lee
 

Paultricounty

Well-known member
United States
Tom, you can be as skeptical as you like, go back to my post giving examples of long distance bino use. When you are familiar with the species that are in a location you don't need to be able to see the detail of their wing coverts or some other tiny detail. For example separating Golden Eagle from White-tailed Sea Eagle isn't too difficult at long distances, same with separating Razorbill from Guillemot, or Kittiwake from gulls. Scanning across mudflats at long distance you won't be able to separate species of Stints but you can tell a Stint from a Dunlin and Godwit from a Curlew and even a Whimbrel from a Curlew, and Ringed Plover from Dunlin.

Lee
At distances of over three football fields? I can barely make out a Buick from a Bentley. 🙁

All I see are birds flying in the far distance , then put the bino down and look through a wide field spotting scope and use the variable magnification eyepiece. I certainly do not have your experience and I don’t doubt that with your experience that you can discern species at nearing a quarter of a mile. But I haven’t been with anybody out birding that has that expertise with 8 or 10 power binoculars. I’m still growing in the hobby and wish one day I have half of your knowledge.

In this instance where we’re discussing (wide FOV at 3 football field distance) and at my level (intermediate at best ) I find I can discern more with high quality glass with very high resolution than average quality mid level wide FOV binos 🙏🏼. I think in this instance (distance) quality is more important than quantity. But I could be wrong.

Paul
 

Troubador

Moderator
Staff member
Supporter
For sure it is possible to have enjoyable and educational wildlife observing with most binoculars whether they have large fields of view or not, nor do they have to be the most expensive top-of-the-line models, and I am happy to note that you 'rarely' wish for more fov than your ELs. Nevertheless bigger fields of view do make many viewing situations easier. On a historical note, I am sure our friend Gijs van Ginkel would confirm that super-large fov is not a recent phenomenon and goes back many decades to the days when porros were the only choice.

Lee
Interestingly I have just been looking at a 1923 catalogue of Zeiss Jena binoculars and three 8x models (Delturis, Delactis and Delturism) are all claimed to have 8.75deg fields of view. and a 1925 Zeiss catalogue lists 2 8x models with fov of 8.5deg and one with 8.75. Considering that one bino brand mentioned to me a couple of years ago that the market for 8x binos is now demanding a fov of 8 it seems there is nothing new under the sun........

Lee
 
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Binastro

Well-known member
I have never had a binocular with too wide a field.

Sometimes the very short eye relief makes EWA binoculars unpleasant to use.

The 8x32 binoculars have shorter focal length eyepieces than 8x42.
That is the reason for the wider field.

The Koehler 120 degree eyepiece was in use about 1943.

B.
 

Swedpat

Well-known member
I have never had a binocular with too wide a field.

Sometimes the very short eye relief makes EWA binoculars unpleasant to use.

The 8x32 binoculars have shorter focal length eyepieces than 8x42.
That is the reason for the wider field.

The Koehler 120 degree eyepiece was in use about 1943.

B.

I know that eye relief of a certain eyepiece design is directly related to the focal length.
But is really the field of view as well? I guess 8x32 and 8x42 use different eyepiece design.
We know that the field stop sets the limit for TFOV, I guess that's the reason that for example 10x42 always have wider AFOV than 7x42.
 

Paultricounty

Well-known member
United States
I know that eye relief of a certain eyepiece design is directly related to the focal length.
But is really the field of view as well? I guess 8x32 and 8x42 use different eyepiece design.
We know that the field stop sets the limit for TFOV, I guess that's the reason that for example 10x42 always have wider AFOV than 7x42.
I thought the same thing but actually it’s not true. Nikon SE binoculars used the same eyepieces for the 32, 42, and 50mm binoculars. 🤯
 

GrampaTom

Well-known member
United States
For sure it is possible to have enjoyable and educational wildlife observing with most binoculars whether they have large fields of view or not, nor do they have to be the most expensive top-of-the-line models, and I am happy to note that you 'rarely' wish for more fov than your ELs. Nevertheless bigger fields of view do make many viewing situations easier. On a historical note, I am sure our friend Gijs van Ginkel would confirm that super-large fov is not a recent phenomenon and goes back many decades to the days when porros were the only choice.

Lee
Lee, it seems you're unwilling to acknowledge what I wrote above that your prior observation I do not bird over territory that has potentially long distances is wrong. I dont get it.

Im not sure the relevance of the point on historical binocular performance. Did I say anything about that?
 

GrampaTom

Well-known member
United States
Those ways of expressing fields of view have been around for many, many decades and using this common method means folks can easily compare binoculars. You keep mentioning 'practical birding distances' as though all birding (indeed all nature observing) takes place at 100 yards or less, despite my having just provided plenty of examples of birding at far greater distances and despite you mentioning San Francisco Bay as the venue for observing by yourself.

Lee
I get that. you know that. I'm not called Grampatom for no reason. But been around for a long time is hardly a reason to keep thinking this way. Please just look at what happens to what seems impressive numbers at 1000, when you reduce linear FOV to more practical birding distances. Underwhelming is the word and the fact. Why do you feel a duty to defend the binocular industry? What about us birders wanting to make better choices? Dont we deserve better information? Here we are on bird forum, one of the few places on the internet where ostensibly folks who share an interest can come together to better understand the tools they use to pursue this wonderful pastime, (birding. not bino buying). As such we can either work our way to better info by interpreting whats published. Or, maybe just maybe, we can influence that old way of saying things by the bino companies so we don't have to squabble over it. Obviously it'd be more credible if XYZ bino company started publishing FOV at 100, rather than this raving old nut claiming they should.

Please dont put words in my mouth or misinterpret. "Practical birding distances" is not an ignorant concept. I said nothing about "all nature observing". I never said it all takes place at 100 yards. In fact much of it takes place at less than that. You know that. There is a practical limit to the effectiveness of an 8 or 10X bino. Thats why theres spotting scopes. The convo here on 12, 15X vs scopes is not uncommon.
 

GrampaTom

Well-known member
United States
Tom, you can be as skeptical as you like, go back to my post giving examples of long distance bino use. When you are familiar with the species that are in a location you don't need to be able to see the detail of their wing coverts or some other tiny detail. For example separating Golden Eagle from White-tailed Sea Eagle isn't too difficult at long distances, same with separating Razorbill from Guillemot, or Kittiwake from gulls. Scanning across mudflats at long distance you won't be able to separate species of Stints but you can tell a Stint from a Dunlin and Godwit from a Curlew and even a Whimbrel from a Curlew, and Ringed Plover from Dunlin.

Lee
No amount of detailing the wonderful birds you see helps make the point. I get one can know birds from an area, especially the larger ones, and can then identify those birds at distances that exceed 100 yards. How many can look at a bird they dont know, from an area they've never been, and identify anything, much beyond that distance. Thats birding to you. Thats fine. Thats not the birding I do, nor for the many people I encounter each year birding in the places I do with extensive distance possibilities. Is the goal to just id whats there? I get for some it is. Though the pleasure in that escapes me. identifying something Ive not seen before is for me and the many I encounter very exciting. Hunting without a gun? Yea, kinda. It feels a bit primal. I cant do that at 1000yds. My greatest joy comes from getting up to 30-40 yards on that pair of Cinnamon Teal still hanging around after the migration and notice the gorgeous colors, the gilt edge on the primaries laying down their back, that incredible red eye, set into the cinnamon colored head. Mother nature is grand. Then there's the black butted Gadwall with similar gilt edged wing feather details.... hmm, are these 2 related by something more than a duck bill and webbed feet? Theres the clunky Brown Pelicans out on the Bay flying along and dive bombing willy nilly whatever they detect swimming along under, vs the Whites, which come in smallish flocks, (at least here), fly and swim like olympic synchronized swimmers with perfect spacing and timing. Whew! 1000 yards? Nah. Black silhouettes that if youre familiar with enable you to identify. if thats your thing, good onya. Is that the thing for many/most? I doubt it.

There was those two guys I met during the Christmas Count ignoring the Red Shouldered Hawk in the tree behind them, 50 yards away, while they peered through their spotter at a Murrelet 300 or so yards out on the Bay, that I had no idea was there with my 10X binos....
 
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