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Why 8x32 are replacing 8x42 (1 Viewer)

eronald

Well-known member
When looking at a bird (Corvis Cornix?) on a tree against a white sky through my Leica Binos today, which are 7x42 Ultravid HD, I realised the bino view was about 2/3 brighter than the direct view.

From there I expect that 7x42 or 8x42 when adopted was historically a lens dimensioning where with older coatings and prism treatments one would have a roughly similarly bright image through a set of binos and direct view.

Today, coatings have got much better, and so if the top bino designs can do 2/3 of a stop better than daylight in 8x42, then similar designs and glass will do roughly equivalent brightness in 8x32.

Which is why people can't be bothered to drag around the 8x42 anymore - in strong sunlight they can dazzle -try the Noctivids to see what I mean- and after dusk they don't really provide a huge advantage. 8x32 on the other hand provide daylight-equivalent brightness at a much smaller size and weight point, at least when they are made by the top brands.

Edmund
BTW. The problem with getting binocular advice from a bird forum is one gets the bird bug. That's now my 3d bird. Boohoo.
 
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Hello Edmund,

My Swarovski 8,5x42 and the Zeiss SF 8x42 are noticeably brighter at twilight than a Nikon EDG 8x32 or a Zeiss Victory 8x32!
In the twilight I still see objects that are only indistinct or unrecognizable in the 8x32!
Do the experiment in the starry sky and you will see how many stars an 8x42 shows more.

Andreas
 
When looking at a bird (Corvis Cornix?) on a tree against a white sky through my Leica Binos today, which are 7x42 Ultravid HD, I realised the bino view was about 2/3 brighter than the direct view.

From there I expect that 7x42 or 8x42 when adopted was historically a lens dimensioning where with older coatings and prism treatments one would have a roughly similarly bright image through a set of binos and direct view.

Today, coatings have got much better, and so if the top bino designs can do 2/3 of a stop better than daylight in 8x42, then similar designs and glass will do roughly equivalent brightness in 8x32.

Which is why people can't be bothered to drag around the 8x42 anymore - in strong sunlight they can dazzle -try the Noctivids to see what I mean- and after dusk they don't really provide a huge advantage. 8x32 on the other hand provide daylight-equivalent brightness at a much smaller size and weight point, at least when they are made by the top brands.

Edmund
BTW. The problem with getting binocular advice from a bird forum is one gets the bird bug. That's now my 3d bird. Boohoo.

Hi, Edmund:

There is NO problem in getting advice from a binocular forum. The only trick is getting accurate advice from there. That, however, is great. Over time, it teaches people some questions can’t be answered simply and some questions simply can’t be answered. :cat:

Bill
 
Birder's are switching to 32mm because they will provide 95% of the performance of a 42mm and you are carrying a much more compact, lighter binocular. If you are over 60 your eyes won't benefit much from the bigger exit pupil anyway. Unless you do a LOT of birding under canopy or at dusk a good 32mm is a lot easier to carry and it will never let you down. I have the SV 8.5x42 FP, SV 8x32 FP, SV 10x32 FP , CL-P compact 8x25 and the Ultravid Compact BCR 8x20 and If I had to get rid of one it would be the SV 8.5x42 FP even though it is an excellent binocular. It is just that the SV 8x32 will do everything the bigger binocular will do with less bulk and weight.
 
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Hi, Edmund:

Over time, it teaches people some questions can’t be answered simply and some questions simply can’t be answered. :cat:

Bill

Hi Bill,

I think most of us who have asked questions of our parents at age 4 have not needed the forum to learn that. 8-P

But maybe we all need an occasional reminder.

Now let's get back to the x32 stuff - how much brightness do people expect from a bino compared to direct view?

Edmund
 
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Eronald,

It is absolutely scientifically impossible for a binocular to deliver any more light to the retina of your eye than you would see directly. As well as the magnification and field of view influencing our perception, binocular designers play psycological games with the, colour spectrum and contrast so you might think you do, but invariably the total light level will be less than seeing directly.

I bright conditions when the pupil of your eye is just 2mm a 8x16 would deliver the same target luminance as an 8x56 providing other physical parameters like the transmission spectrum were the same.

Hope that's clear. ;)

David
 
Maybe I`m weird, but my 42mm SV is clearly brighter than my 32mm SV, every time, I fully understand that in bright light our pupils stop down smaller than the 4mm exit pupil of the 32mm, but for me in the same light the 42mm is just more dynamic.

I feel the opposite to Dennis, (nice to see you back Dennis), I would hold on to the 42mm over the 32.
 
Maybe I`m weird, but my 42mm SV is clearly brighter than my 32mm SV, every time, I fully understand that in bright light our pupils stop down smaller than the 4mm exit pupil of the 32mm, but for me in the same light the 42mm is just more dynamic.

I feel the opposite to Dennis, (nice to see you back Dennis), I would hold on to the 42mm over the 32.

Brightness is a perception, not a measure of light levels. You might say it's a figment of your imagination, but in reality it's often in response to a difference in some physical parameter or another. It might be some small difference in spectrum, contrast, resolution or glare is enough makes a perceptual difference, but It is also in the nature of psychology that if you expect the x42 to be brigher, it may well appear to be. ;)

David
 
I agree with Torview (post 7); 42mm seems more dynamic and I think it's a nice useful combo to have a
42mm and 30/32mm on hand.

If I never needed to wear glasses I would most likely have a 8x32 and 10x32. I'd probably never discover the benefits of 42mm bins and wouldn't have my 7x42 Ultravid. A positive side effect of wearing glasses is discovering how wonderful 7x42 is. I had trouble in the beginning adjusting to looking through bins with eyeglasses and needed to go up from 8x32 binos (always my fav format) to 42mm for the larger exit pupil. But I found I do really enjoy 42mm for its larger window view , more comfortable, better glare control... As Torview says, more dynamic .

With that said, if I suddenly didn't have to wear glasses anymore I'd probably use 32mm as my main binocular for the smaller size and lighter weight benefits. I do still love smaller binoculars and that's why I have an 8x30 as well to go along with 7x42.

My future and final binocular purchase may be a 8x32 once I find 42mm to be too heavy when I'm older. I'm ok now with the weight but someday I may want to use 42mm much less and go with a top 8x32 to take over as main binocular. It will most likely be EL
SV 8x32. That's the one I have in mind IF I can even afford it down the road. If not, I'm ok
with the 2 wonderful binos I already have.
 
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Maybe I`m weird, but my 42mm SV is clearly brighter than my 32mm SV, every time, I fully understand that in bright light our pupils stop down smaller than the 4mm exit pupil of the 32mm, but for me in the same light the 42mm is just more dynamic.

I feel the opposite to Dennis, (nice to see you back Dennis), I would hold on to the 42mm over the 32.
Thanks! I have no intention of getting rid of the 8.5x42 SV. I know I would be sorry later on. It is so perfect optically. I do like the smaller, lighter binoculars lately though. I am even starting to tolerate the compacts and have been using the Swarovski CL-P 8x25 and Leica Ultravid BCR 8x20 quite a bit. They are more fussy but they are just so light and compact to carry. Maybe it is because I am getting older and weaker!
 
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Some prefer the larger exit pupil, 5.25 or 5 in a 10X50 for easy eye placement, and they do not have a problem with an instrument that weighs 800 to 1000 grams, some hardly use 8X32. These are individual choices, not one size fits all.

Andy W.
 
To be politically correct, we may acknowledge that the "minority" of those who are under 60 should be recognised as fully enfranchised binocular buyers and users, and then an exit pupil over 4mm does make a visible difference :)

Which would mean that all the light gathered eg by an 8x42 *could* find its way to the retina of one of these "minority users", and there would be substantially more of this light than an equivalent 8x32 would send to the same person's rods and cones. The 42 would be perceptually brighter than the 32, provided of course you belong to this "youthful minority".

I don't want to have a tech discussion on a subject I don't understand; what interests me more is the subjective perception of buyers, and my feeling is that the general adoption of the 42 had something to do with a brightness threshold, a feeling when taking up the glasses and putting them down, and that modern tech has moved this threshold so it is now located at 32. I'd like to pin down that feeling.

Edmund
 
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Hi Edmund (post 12),

When I decided to go with 7x42 it didn't have anything to do with needing a brighter binocular. For me, it was about comfort with eyeglasses. I was finding the smaller exit pupil of 30/32mm binoculars to be too picky and bothersome when wearing glasses. A bigger EP makes much easier and more comfortable viewing and an ability to get on the birds quicker. There's no fuss when bringing the bino up to my eyes, as there's essentially no need to work at getting the EP of the bino properly aligned with my eyes. So, for me it was about ease of view mainly. However, I do think the 7x42 works very well for me on dreary days when the sun is hiding and at dusk. I'm rarely out during dusk, but this Spring/Summer I will be out occasionally as the sun goes down for a bit. Now that I have thinner eyeglass frames I find my 8x30 easier to use, but the 7x42 still much better.
 
Some prefer the larger exit pupil, 5.25 or 5 in a 10X50 for easy eye placement, and they do not have a problem with an instrument that weighs 800 to 1000 grams, some hardly use 8X32. These are individual choices, not one size fits all.

Andy W.
I think it depends on your age.;) The older I get the more I appreciate the size and weight of an 8x32 and the bigger exit pupil of an 8x42 becomes less of an advantage.
 
I think it depends on your age.;) The older I get the more I appreciate the size and weight of an 8x32 and the bigger exit pupil of an 8x42 becomes less of an advantage.
It's entirely an individual thing. Approaching 60, my father lugged around a 7x50 Zeiss rather than the smaller roof prisms he had also tried, and I've used myself for decades. Now I too find myself falling in love with 56mm SLCs, and imagining that I finally understand why. Except I don't... perhaps there are subtleties to dealing with a larger exit pupil, beyond performance in low light?
 
... perhaps there are subtleties to dealing with a larger exit pupil, beyond performance in low light?

There are. Uncritical pupil positioning from the large EP and effectively lower aberrations in bright light from the stopdown imposed by the eye's pupil make the view through my Zeiss 8x56 FL superior to any smaller binocular I've tried, especially the 30-32mm squirts.
 
When looking at a bird (Corvis Cornix?) on a tree against a white sky through my Leica Binos today, which are 7x42 Ultravid HD, I realised the bino view was about 2/3 brighter than the direct view.

From there I expect that 7x42 or 8x42 when adopted was historically a lens dimensioning where with older coatings and prism treatments one would have a roughly similarly bright image through a set of binos and direct view.

Today, coatings have got much better, and so if the top bino designs can do 2/3 of a stop better than daylight in 8x42, then similar designs and glass will do roughly equivalent brightness in 8x32.

Which is why people can't be bothered to drag around the 8x42 anymore - in strong sunlight they can dazzle -try the Noctivids to see what I mean- and after dusk they don't really provide a huge advantage. 8x32 on the other hand provide daylight-equivalent brightness at a much smaller size and weight point, at least when they are made by the top brands.

Edmund
BTW. The problem with getting binocular advice from a bird forum is one gets the bird bug. That's now my 3d bird. Boohoo.

Eronald,

It is absolutely scientifically impossible for a binocular to deliver any more light to the retina of your eye than you would see directly.... David
+ 1 :t: with all that David said

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Edmund - it depends ! All of what you have said is highly subjective ..... :cat:

With the advent of 42mm bins like the Minox APO's, and the Nikon Monarch HG's, etc, you have fairly compact fairly light 'full' size bins that change the paradigm somewhat .....

Personally I love the way the MHG feels in the hand, and ergonomics-wise I wouldn't want to go smaller than this - it is super stable for me. With some high tech materials it could be even lighter - matching the x32mm's. My only wish was that it was a bit sharper etc to put it clearly on top of the heap.

And yes I am young enough to notice the brightness effects of less than 5.25mm EP in low light /canopy shade /sunset etc.

In comparison, the rather lovely Swarovski x32mm feels a bit small in the hand and a bit more involved to hold steady. Though I love the tan colour of the armour and the easy view, if I had to choose a light weight bin to hold - it would be the MHG.

Each to there own and more power (and/or objective size ! :) for it :t: , but let's not add to the Internet mythology, lest we have Lee come along and start quoting 'field of volume' in km3 ! to really set the cat :cat: among the pigeons :flyaway: ...... :-O






Chosun :gh:
 
I prefer the 32 format because of the weight and size. I use mine while hiking in the backcountry quite often so they work quite well for that. Having said that I can appreciate others favoring the 42 and bigger sizes. We all have different preferences and it’s great to have so many choices with modern optics.
 
Brightness is a perception, not a measure of light levels. You might say it's a figment of your imagination, but in reality it's often in response to a difference in some physical parameter or another. It might be some small difference in spectrum, contrast, resolution or glare is enough makes a perceptual difference, but It is also in the nature of psychology that if you expect the x42 to be brigher, it may well appear to be. ;)

David

That David seems always to be around with all that ... LOGIC CRAP. Too many people see a binocular as aperture, magnification, and possibly coatings. In the REAL world, there is a bit more to consider leading to real or imagined image brightness:

1. Smoothness of optical surfaces
2. Precision in design (caring or understanding)
3. Best choice in selecting glass types, curvatures, and spacings
4. Precision in manufacturing
5. Precision in testing
6. Primary and secondary baffling
7. Edge blackening (a lost art)
8. Slotted prisms (in Porros)
9. Size and position of the field stop
10. Knife edge on that stop
11. Number of elements in the eyepiece
12. Type of eyepiece
13. More

14. Personal physiology and PERCEPTION

In most cases, #14 will supersede the previous 13 :cat:

Bill
 
That David seems always to be around with all that ... LOGIC CRAP. Too many people see a binocular as aperture, magnification, and possibly coatings. In the REAL world, there is a bit more to consider leading to real or imagined image brightness:

1. Smoothness of optical surfaces
2. Precision in design (caring or understanding)
3. Best choice in selecting glass types, curvatures, and spacings
4. Precision in manufacturing
5. Precision in testing
6. Primary and secondary baffling
7. Edge blackening (a lost art)
8. Slotted prisms (in Porros)
9. Size and position of the field stop
10. Knife edge on that stop
11. Number of elements in the eyepiece
12. Type of eyepiece
13. More

14. Personal physiology and PERCEPTION

In most cases, #14 will supersede the previous 13 :cat:

Bill

I think the 'physical parameters' etc that David refers to are probably the result of aspects listed by Bill - one being the consequence of the other.
 
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