[FrankD]

Originally Posted by denco@comcast.n

"I'd like to try the 7x50 vixen"

I think you would send them back. The small FOV and eyecups that are too big will be a dealkiller for you. They present a different 3D view that is relaxing but it is not up to an SE, EDG or SV. Save your time.

Hee Hee. Keep telling yourself that.

[denco@comcast.n]

Originally Posted by Hermann

Agreed. That's a *huge* advantage of large exit pupils, and in my opinion the main reason why many people love their 7x42's so much. Compared to the ease of use all the other parameters (such as large field of view and large depth of field) are fairly insignificant in my opinion.



Agreed. Many binoculars with large exit pupils have very high image quality in bright daylight, and the best of them are better optically than the best medium-sized binoculars.



While true I don't think this is *that* important in most birding situations. The resistance to veiling glare *can make a difference*, but the best of the smaller binoculars are already pretty good when it comes to dealing with internal reflections.



I personally don't see any really significant difference here. The image as a whole just looks "nicer"; maybe the lack of vignetting contributes to this, but I don't know how much. I certainly don't notice the vignetting in the field. That's something I'll have to look at more closely in the field.



The weight is the killer as far as I'm concerned. I find I can hold binoculars weighing between 650 and 850 gr steadier than lighter or heavier binoculars, for instance when scanning the seashore or the edge of a wood for any length of time. It's only in high winds or on a boat that I find heavy binoculars easier to hold steady than lighter binoculars, and for my kind of birdwatching the big binoculars are just too heavy. As much as like good 8x56's or, better still, 8x50's, they're well above the weight I'm comfortable with.

I agree pretty much with you Hermann I just differ on a few points.

Hermann

Quote:
Originally Posted by henry link
This has all been discussed here before, so I’ll just briefly list some of the advantages.

1) Greater viewing comfort: Large exit pupils are very forgiving of eye placement compared to small ones.
Agreed. That's a *huge* advantage of large exit pupils, and in my opinion the main reason why many people love their 7x42's so much. Compared to the ease of use all the other parameters (such as large field of view and large depth of field) are fairly insignificant in my opinion.

Disagree)I don't see the HUGE advantage to large exit pupils in birding situations. I have no problem whatsoever with eye placement with my 8x32 EDG's.

Quote:
Originally Posted by henry link
2) Lower aberrations: Even when the optics are quite ordinary at full aperture, most 7mm exit pupil binoculars show very low aberrations when stopped down to 2-3mm by the pupil of the eye in bright light.
Agreed. Many binoculars with large exit pupils have very high image quality in bright daylight, and the best of them are better optically than the best medium-sized binoculars.

Disagree) I think with the modern roofs there are very little aberrations anyway and it isn't worth carrying a huge heavy binocular to get that last 1 to 2 % of performance.

Quote:
Originally Posted by henry link
3) High resistance to veiling glare: In bright light, even if there is an internal reflection at the edge of a large exit pupil it falls harmlessly on the iris rather than entering the eye. The very same reflection that causes flare in an 8x32 will be quite invisible in an 8x56.
While true I don't think this is *that* important in most birding situations. The resistance to veiling glare *can make a difference*, but the best of the smaller binoculars are already pretty good when it comes to dealing with internal reflections.

Disagree) Most of the best 8x32's are very good at controlling veiling glare the way it is. Especially the Nikon SE. You can look almost directly at the sun with no glare problems. You don't need a 56mm aperture.

Quote:
Originally Posted by henry link
4) Wider area of full illumination: All binoculars show off-axis vignetting from undersized prism apertures. At full aperture there is usually only a small area in the field center that actually receives light from the entire objective lens.
I personally don't see any really significant difference here. The image as a whole just looks "nicer"; maybe the lack of vignetting contributes to this, but I don't know how much. I certainly don't notice the vignetting in the field. That's something I'll have to look at more closely in the field.

Disagree) I don't notice his to any signifigant extent in the field either.

Quote:
Originally Posted by henry link
5) I've become quite convinced that I can hand hold my big 43 oz 8x56 steadier than smaller, lighter binoculars. The extra mass appears to dampen high frequency tremors, leaving a slower roll that allows glimpses of extra detail. They are certainly murder on the neck, so I use them with a harness and can hike all day with no complaint.
The weight is the killer as far as I'm concerned. I find I can hold binoculars weighing between 650 and 850 gr steadier than lighter or heavier binoculars, for instance when scanning the seashore or the edge of a wood for any length of time. It's only in high winds or on a boat that I find heavy binoculars easier to hold steady than lighter binoculars, and for my kind of birdwatching the big binoculars are just too heavy. As much as like good 8x56's or, better still, 8x50's, they're well above the weight I'm comfortable with.

Disagree) I certainly disagree with this! A 56mm binocular is way to big for birding and there is no way I am going to carry one in the field. The small increase in performance is not worth the weight and discomfort.

The modern 32mm will give most birders all the performance they need and in my opinion it is not worth it to carry a 50mm or above binocular for the small increase in performance you are going to see.

[denco@comcast.n]

Originally Posted by FrankD

Hee Hee. Keep telling yourself that.

Frank . They were good and they were different. They just were not keepers for me. Those eyecups are just weird! You would have to have eyes like a gorilla for them to fit.

[Brigadier]

Henry, Surveyor and all, thank you for your interesting insight into the performance advantages of large aperture binoculars. We seem to be dividing into two camps here: perfectionists and pragmatists.

Perfectionists, like Henry, with their deep understanding of optics, want the best performance possible and are prepared to compromise everything else to get it: size, weight, cost and discomfort. This is more the talk of astronomers than birders.

Pragmatists, like me, regard a binocular primarily as a tool to help identify and study birds and wildlife. We're practical folk; we try to strike a sensible balance between performance and utility. We accept that 56mm objectives might give us slightly better aberration control and slightly more even image illumination, but we know that after a few hours of lugging around a 1.2kg binocular we'd feel too tired and miserable to want to look at anything.

That's why I still think that, with modern optical technology, a quality 8x30-32 binocular is the best compromise for most birders, most of the time. And, quite frankly, it isn't much of a compromise.

[Robert Wallace]

Thank you Henry and others for developing my knowledge and understanding of binocular brightness and for the thought provocing discussions.
I can cheerfully return to using my 7x42!
The Brigadier is absolutely right in suggesting that 8x30/32s are more than adequate for birdwatchers and this is evidenced in the UK by a number of very distinguished birders/naturalists using the smaller objectives. The late Desmond Nethersole Thompson springs to mind, with his Zeiss (West) 8x30B porros.
People are different and you pays yer money and takes yer choice.
While I agree that a quality 8x30/32 binocular is the best for most birders I understand most birders prefer 42mm objectives, even when they reach my age.
I disagree with Dennis regarding FOV, I think this contributed to the popularity of the Zeiss 7x42 which had a greater FOV than 8x roofs and matched that of most 8x30 porros.
Fascinating to see Dennis defending his 8x32s althought didn't he support the Zeiss FL 8x56 some time back as the best binocular?

[newfie ghost]

Originally Posted by hinnark

Hi Newfie, you deserve the award for the most interesting questions lately. :)

Additional to what was written already, here are my two cents. The aperture size of bincoulars doesn't have an effect on eye relief. This is just a property of the eyepiece design. Since I've become an addictive of wide sweet spots and sharp edges I have to say that the eye pupil stop down on large exit pupils of eyepieces doesn't help my eyes much to reduce astigmatism towards the edges, if present.

Monster bins I like are for example 10x70 Fujinon FMT-SX as well as its small brother 7x50. BTW Fujinon does produce a FMT 8x50 model as well. All of them do have a remarkable relaxed view. Vixen has interesting and surprising lightweight 9x63 Ultima binoculars. The 8x56 isn't that bad for the price as well. BTW all that Ultimas seem to use the same prisms, eben the 8x32 one. If one is looking for an 8x56 with a pretty wide field and sweet spot alltogether with long eye relief, take a look at the Optylyth Vianova 8x56. It has one of the largest eyepiece lenses I know.

Conclusion: My hands do like the big guns because they have something to grab, but my neck and back don't. So I prefer to use them when the time of the day comes for their specific purpose from dusk to dawn.

Steve

Thanks Steve!

[denco@comcast.n]

Originally Posted by Brigadier

Henry, Surveyor and all, thank you for your interesting insight into the performance advantages of large aperture binoculars. We seem to be dividing into two camps here: perfectionists and pragmatists.

Perfectionists, like Henry, with their deep understanding of optics, want the best performance possible and are prepared to compromise everything else to get it: size, weight, cost and discomfort. This is more the talk of astronomers than birders.

Pragmatists, like me, regard a binocular primarily as a tool to help identify and study birds and wildlife. We're practical folk; we try to strike a sensible balance between performance and utility. We accept that 56mm objectives might give us slightly better aberration control and slightly more even image illumination, but we know that after a few hours of lugging around a 1.2kg binocular we'd feel too tired and miserable to want to look at anything.

That's why I still think that, with modern optical technology, a quality 8x30-32 binocular is the best compromise for most birders, most of the time. And, quite frankly, it isn't much of a compromise.

I am a pragmatists. I tried Henry's Zeiss 8x56 FL and my back still feels it. Give me an 8x32 of good quality and I am happy. Preferably SE or EDG.

[denco@comcast.n]

Originally Posted by Robert Wallace

Thank you Henry and others for developing my knowledge and understanding of binocular brightness and for the thought provocing discussions.
I can cheerfully return to using my 7x42!
The Brigadier is absolutely right in suggesting that 8x30/32s are more than adequate for birdwatchers and this is evidenced in the UK by a number of very distinguished birders/naturalists using the smaller objectives. The late Desmond Nethersole Thompson springs to mind, with his Zeiss (West) 8x30B porros.
People are different and you pays yer money and takes yer choice.
While I agree that a quality 8x30/32 binocular is the best for most birders I understand most birders prefer 42mm objectives, even when they reach my age.
I disagree with Dennis regarding FOV, I think this contributed to the popularity of the Zeiss 7x42 which had a greater FOV than 8x roofs and matched that of most 8x30 porros.
Fascinating to see Dennis defending his 8x32s althought didn't he support the Zeiss FL 8x56 some time back as the best binocular?

My back still winces even when I think of them. They are huge.

[hinnark]

Originally Posted by Surveyor

(6) The higher resolution, and hence, contrast (MTF) of the larger lens.

Folks can check this out for themselves by taking a small aperture and large aperture bino, of the same power, out and finding something like a distant radio tower or transmission line, something with a lot of straight lines in it. You will see the same thing through both as far as the cross members but the larger lens, even though no sharper at the edges of the cross members (limited by your eyesight) you should see them as being a little darker than the smaller lenses. This is the MTF (contrast) at work. Almost always will the larger be better unless a lot worse than the smaller example optically.

Hi Ron,

I suppose what you're describing is the same effect when watching circling raptors. I have had always the impression that large aperture binos show more and better details of the plumage than those of smaller aperture, for instance a 10x50 more than a 10x30 assuming the optical quality of those two is comparable.

Steve

[Robert Wallace]

You may gather that I am a bit of a fan of the late Desmond Nethersole-Thompson he was a bit of a character. In one of his books (Highland Birds 1971) he divided bird watchers into two main groups - "leggers and arses". Leggers move around from "good spot" to "good spot" whereas arses tend to me more patient staying in one preferred location to observe carefully. Clearly from what we have learned above, 8x32 for leggers and 8x56 for arses. Please no offence intended Henry, I should add D N-T was by his own admission an arser, a great observer of waders especially the greenshank.
Silly thought 42mm for the "inbetweenies"?

[Chosun Juan]

Newfie,

I used to use a Gerber 7x50 porro. They are something like a sports store brand, with a slightly warmer than neutral view, narrow FOV (for a 7x), luxurious ER (somewhat squandered by the near 10mm of ocular recess), distinct false exit pupils, CA straight out of a 60's London nightclub, and about 1kg in weight. All in all, not much to recommend them, and yet at times (admittedly few and far between) the view through them was as good as anything (swaro et al incl).

I would agree with the points henry made, as potential advantages.
(my additions in bold italics)

Originally Posted by henry link

1) Greater viewing comfort:- When you have a peregrine falcon unexpectedly turn up and start whizzing around your scone, being able to just throw bins up to your eyes with ep to spare is a great luxury, especially when your shakin' like a dog sh*tt*n razor blades!

2) Lower aberrations: Even when the optics are quite ordinary at full aperture, most 7mm exit pupil binoculars show very low aberrations when stopped down to 2-3mm by the pupil of the eye in bright light. Yup. some of those few and far between times.

3) High resistance to veiling glare: In bright light, even if there is an internal reflection at the edge of a large exit pupil it falls harmlessly on the iris rather than entering the eye. Yes. These "very ordinary" bins sometimes punched well above their weight in glary situations, and the false ep's were almost never visible (and when it was dark enough for your eyes to dilate to 7mm - the sun was long gone anyway).

4) Wider area of full illumination: .....In bright light the geometry changes, so that large exit pupil binoculars are less subject to off-axis vignetting that small ones. Yup. some more of those few and far between times.

5) I've become quite convinced that I can hand hold my big 43 oz 8x56 steadier than smaller, lighter binoculars. Your on your own here Henry! After a run in with gravity in which I came off decidedly second best, the 1kg is annoying for birding, and only provides some reassurance when some of the big buck roos around here decide that they don't like the idea of you humping their missus, and come barrelling over looking for a blue!

So the advantages are certainly there (in addition to what RonE, and Essex Tern wrote) ....... only you can decide how much they mean to you, and whether that last few poofteenths of a percent outweighs the compromises (weight, less FOV - from the usually large ER and economising on prism size due to weight).

I personally have resigned the Gerber's to "ex" status (although we are still good friends.....) since I don't find any boat floating with a mere 7x 'round here, prefer a neutral tone view, and refuse to live with a giant fatty boombah heffalump (especially after the bin strap broke one day sending 1kg of rapidly accelerating metal careening for my open-toed sandals! Ouch! caught them with mere inches to spare - phew!)

Perhaps if you go down this path, you might consider attaching a helium balloon to each barrel??


Chosun

[ronh]

Henry's argument largely hinges on the small eye pupil's isolation of the central "sweet central path" through the optics, where one effectively looks through a very nice f/10 to f/15 telescope. That is compelling, theoretically!

But in practice, fully realizing this advantage requires that the IPD match the eyes, and that the binocular be positioned so that the eyes are accurately centered on the eypieces. Otherwise, an off centered, tilted piece of the optics could be isolated. This off center path could be poor indeed, if it came at the edge of an objective where it was pinched its cell, and through a simple eyepiece at a steep angle. So, unless you are really skilled at positioning the binocular, it seems that the large exit pupil might sometimes please, and sometimes dissappoint.

I think this is what happens when, with my 7x50, I sometimes experience rather nasty lateral color, even in the center of the view. My experiments with glitter points, and also looking at the reflection of my pupils in a mirror through binoculars, confirm my surprisingly poor abilities to match the IPD to my true eye separation, and to center my eyes behind the eyepieces.

I do very much like the view in my 7x50 neverthess, and although there are some variations as I have tried to understand, overall it mostly works out like Henry says. But with a small exit pupil, you can be more assured that you are in fact getting the "sweet central path", as well as other less desirable paths, into your eye.
Ron

[CharleyBird]

I have a pair of 9x63 inpro, an impulse fun buy, on special offer at about £150 which gives you an idea of their relatively poor quality compared to the Zeiss 8x56 Henry Link uses.

The are too heavy for me to comfortably carry far (see Henry's solution to weight problems), and sometimes make me squint in bright sunlight, especially on a light
background.

I keep them at work as they are nice used propped against open windows and walls of the building when looking at LBB's in the bushes in the grounds.

[newfie ghost]

Originally Posted by Chosun Juan

Newfie,

I used to use a Gerber 7x50 porro. They are something like a sports store brand, with a slightly warmer than neutral view, narrow FOV (for a 7x), luxurious ER (somewhat squandered by the near 10mm of ocular recess), distinct false exit pupils, CA straight out of a 60's London nightclub, and about 1kg in weight. All in all, not much to recommend them, and yet at times (admittedly few and far between) the view through them was as good as anything (swaro et al incl).

I would agree with the points henry made, as potential advantages.
(my additions in bold italics)



So the advantages are certainly there (in addition to what RonE, and Essex Tern wrote) ....... only you can decide how much they mean to you, and whether that last few poofteenths of a percent outweighs the compromises (weight, less FOV - from the usually large ER and economising on prism size due to weight).

I personally have resigned the Gerber's to "ex" status (although we are still good friends.....) since I don't find any boat floating with a mere 7x 'round here, prefer a neutral tone view, and refuse to live with a giant fatty boombah heffalump (especially after the bin strap broke one day sending 1kg of rapidly accelerating metal careening for my open-toed sandals! Ouch! caught them with mere inches to spare - phew!)

Perhaps if you go down this path, you might consider attaching a helium balloon to each barrel??


Chosun

Thanks for the post

[Brigadier]

Originally Posted by Robert Wallace

You may gather that I am a bit of a fan of the late Desmond Nethersole-Thompson he was a bit of a character. In one of his books (Highland Birds 1971) he divided bird watchers into two main groups - "leggers and arses". Leggers move around from "good spot" to "good spot" whereas arses tend to me more patient staying in one preferred location to observe carefully. Clearly from what we have learned above, 8x32 for leggers and 8x56 for arses. Please no offence intended Henry, I should add D N-T was by his own admission an arser, a great observer of waders especially the greenshank.

Nice story. I once knew an old-timer - a "legger" - with a beaten-up 8x30 porro, a 1960s Ross I think. He always got more IDs than me with my (then) new Nikon 8x30 EII, which just goes to show: it isn't what you've got, it's how you use it.

[normjackson]

Originally Posted by Brigadier

which just goes to show: it isn't what you've got, it's how you use it.

Hens worldwide roll eyes in unison...