best low light bino 10x (1 Viewer)

Re variation in dark adapted pupil size, here is some actual data from a 2011 study. https://www.ncbi.nlm.nih.gov/pubmed/20506961

Two-hundred sixty-three individuals participated. For participants aged 18 to 19 years (n=6), the mean dark-adapted pupil diameter was 6.85 mm (range: 5.6 to 7.5 mm); 20 to 29 years (n=66), 7.33 mm (range: 5.7 to 8.8 mm); 30 to 39 years (n=50), 6.64 mm (range: 5.3 to 8.7 mm); 40 to 49 years (n=51), 6.15 mm (range: 4.5 to 8.2 mm); 50 to 59 years (n=50), 5.77 mm (range: 4.4 to 7.2 mm); 60 to 69 years (n=30), 5.58 mm (range: 3.5 to 7.5 mm); 70 to 79 years (n=6), 5.17 mm (range: 4.6 to 6.0 mm); and 80 years (n=4), 4.85 mm (range: 4.1 to 5.3 mm).

Note how wide the ranges are. My point is that the simple line graph showing how maximum dilation changes with age is not telling the whole story. Also, I don't believe that having your pupils dilated by an ophthalmologist with drugs necessarily tells you what your dark adapted maximum will be.

Alan

ailevin said:

Re variation in dark adapted pupil size, here is some actual data from a 2011 study. https://www.ncbi.nlm.nih.gov/pubmed/20506961

Two-hundred sixty-three individuals participated. For participants aged 18 to 19 years (n=6), the mean dark-adapted pupil diameter was 6.85 mm (range: 5.6 to 7.5 mm); 20 to 29 years (n=66), 7.33 mm (range: 5.7 to 8.8 mm); 30 to 39 years (n=50), 6.64 mm (range: 5.3 to 8.7 mm); 40 to 49 years (n=51), 6.15 mm (range: 4.5 to 8.2 mm); 50 to 59 years (n=50), 5.77 mm (range: 4.4 to 7.2 mm); 60 to 69 years (n=30), 5.58 mm (range: 3.5 to 7.5 mm); 70 to 79 years (n=6), 5.17 mm (range: 4.6 to 6.0 mm); and 80 years (n=4), 4.85 mm (range: 4.1 to 5.3 mm).

Note how wide the ranges are. My point is that the simple line graph showing how maximum dilation changes with age is not telling the whole story. Also, I don't believe that having your pupils dilated by an ophthalmologist with drugs necessarily tells you what your dark adapted maximum will be.

Alan

Click to expand...

Really range in statistics is meaningless. That could mean one 50 year old person had a pupil diameter of 7.2mm out of the group but the average was 5.77mm. When you get over 50 stick with a 5mm exit pupil. Get an 8x42, 10x42, 10x50 , 10x54 or 10x56. A 10x70 or 10x80 is wasted light and a monster to carry.

For me the benefit of larger exit pupil is viewing comfort with glasses and not so much the extra brightness.
But, I have to say on days like today which was gray and drizzling the 7x42 helps. Despite the rain I still saw some warblers, vireos and lots of fall sparrows.
If I didn't wear glasses I'd most likely use a 32mm as primary bino.

Gilmore Girl said:

For me the benefit of larger exit pupil is viewing comfort with glasses and not so much the extra brightness.
But, I have to say on days like today which was gray and drizzling the 7x42 helps. Despite the rain I still saw some warblers, vireos and lots of fall sparrows.
If I didn't wear glasses I'd most likely use a 32mm as primary bino.

Click to expand...

:t:

ailevin said:

Re variation in dark adapted pupil size, here is some actual data from a 2011 study. https://www.ncbi.nlm.nih.gov/pubmed/20506961

Two-hundred sixty-three individuals participated. For participants aged 18 to 19 years (n=6), the mean dark-adapted pupil diameter was 6.85 mm (range: 5.6 to 7.5 mm); 20 to 29 years (n=66), 7.33 mm (range: 5.7 to 8.8 mm); 30 to 39 years (n=50), 6.64 mm (range: 5.3 to 8.7 mm); 40 to 49 years (n=51), 6.15 mm (range: 4.5 to 8.2 mm); 50 to 59 years (n=50), 5.77 mm (range: 4.4 to 7.2 mm); 60 to 69 years (n=30), 5.58 mm (range: 3.5 to 7.5 mm); 70 to 79 years (n=6), 5.17 mm (range: 4.6 to 6.0 mm); and 80 years (n=4), 4.85 mm (range: 4.1 to 5.3 mm).

Note how wide the ranges are. My point is that the simple line graph showing how maximum dilation changes with age is not telling the whole story. Also, I don't believe that having your pupils dilated by an ophthalmologist with drugs necessarily tells you what your dark adapted maximum will be.

Alan

Click to expand...

Thanks Alan,

That's the data Ed presented a while ago which shows much greater dilation than commonly recognized or thought of for various ages. Since it has both mean and range data from mostly statistically significant sample sizes then even Dennis should find it useful ...... :cat:

I still believe the question of actual 'best seeing' though is a complex relationship between brightness, acuity, magnification, and the distortion characteristics of the individuals eyes wrt to dilation diameter, among other things.

A large enough and well designed and controlled study could produce some statistically relevant mathematical modeling ...... though I bet it would be no simple task! :brains:



Chosun :gh:

I just checked my attic

ailevin said:

Ed,

...
You believe I misunderstand what a field stop does. I believe you misunderstand what an exit pupil is, how an image is formed by an objective, the role of the ocular, and how the field stop of an ocular figures in the design and function of the combined objective/ocular system.

These are not merely matters of preference or personal opinion. They are also not issues of perception or physiology. For this reason, I would be happy to see what an optics designer or physicist/engineer with expertise in optics, has to say about our exchange with regard to the images produced by different optical instruments.

Best Regards,
Alan

Click to expand...

Alan,

To state the obvious you are doubling down on your earlier comment: "... [the] field stop does not necessarily decrease the light throughput while looking on axis, or over large portions of the field of view." Is that correct?

Unfortunately, "optics designers" do not appear, Deus ex machina, to resolve our silly disputes on BF. That's what reference books are for. So, I have attached pg. 234-5 of Warren J. Smith's classic, Modern Optical Engineering, The Design of Optical Systems, 1990. Nothing I've said is inconsistent with it, or, for that matter, any of my other optics books. Diaphragm #2 is the field-stop in Fig. 6.2. The first sentence in sect. 6.3 says that it prevents principal rays beyond a certain distance from the axis from passing through the system [to the image]. Of course, if the field-stop aperture were smaller, less would get through — or in the extreme, nothing. If you still think you're right I'd be happy to read a qualified reference of your own. Absent that, I have nothing more to discuss with you on this subject.

--------------------------

For those interested in birding binocular esoterica, it wasn't recognized until recently that many discrepant visual science studies dealing with human pupil diameter could be brought into correspondence by correcting for corneal flux density (or adapting field area). This discovery can probably be attributed to Prof. David Atchison, et al, Queensland University of Technology, Australia in 2011. The laboratory work was done under photopic (daylight) and mesopic (twilight) viewing conditions. The unified formula for pupil size was then developed by Watson & Yellott, which utilized those findings and many others. [Note that Allbinos' ratings don't even incorporate FOV, so they probably couldn't care less.] But it does have to do with the enigma of instrument brightness — which, like it or not, is psychophysiological response.

I have asked BF management to establish a Technical forum so issues like this don't have to bore everyone not interested. I'll try again.
--------------------------

Oh, one other thing. Someone please look up the meaning of r-squared. It really covers all the concerns I've seen expressed on previous posts having to do with data/sample variability.

Cheers, B
Ed

Hello bird forum,

I did not read this thread completely, so I do not know if this was mentioned (or sth. similar):
https://homepages.uni-tuebingen.de/martin.adler/pup_age.html

So pupil size and age matter, and all depends.

To try an answer to the initial question (best low light bino 10x): It depends.

If your pupil doesn't get larger than 5.3 or so mm, the Zeiss is brighter (the transmission at night is higher).
If it gets larger than 5.5, the Swaro should catch up a bit.
If it ever get's visibly brighter than the Zeiss I doubt.
The influence of a larger aperture on the abberations of your built-in optical system no one can guess.
(I see this almost never discussed: the image that your eye provides may get significantly worse if your pupil (or the aperture of the complete optical systen, e.g. including bino) widens).
Whether you like the view through the Zeiss better or the one through the Swaro I don't know.

Try them, buy the one that you fall in love with and enjoy. In the optics there is hardly any difference of practical significance.

martin aka cocco (a forum newbie).

"In the optics there is hardly any difference of practical significance."

Under most circumstances, you would be correct. BUT, this is BirdForm where we like to "split hairs with an ax" and seek solutions to problems that don't exist. Sometimes the science is highlighted and propagated--which is great--but our physiological differences muddy the issues into the impractical.

Bill

WJC said:

"In the optics there is hardly any difference of practical significance."

Under most circumstances, you would be correct. BUT, this is BirdForm where we like to "split hairs with an ax" and seek solutions to problems that don't exist. Sometimes the science is highlighted and propagated--which is great--but our physiological differences muddy the issues into the impractical.

Bill

Click to expand...

You nailed that one Bill. Don't forget how many reviews we get, especially on "new to the market binos", by people that have never laid eyes or hands on them. I love those.

Bill, thanks for your valuable hint.

WJC said:

this is BirdForm where we like to "split hairs with an ax"

Click to expand...

I hope to learn that soon.

cocco

cocco said:

Bill, thanks for your valuable hint.



I hope to learn that soon.

cocco

Click to expand...

It's very much like the audio forums (fora?) where they argue over which cable "sounds better".

jgraider said:

You nailed that one Bill. Don't forget how many reviews we get, especially on "new to the market binos", by people that have never laid eyes or hands on them. I love those.

Click to expand...

Yes, but it’s better than over at CN, where two of those with the MOST to say consistently offer the LEAST worth listening to. My heart just cries at some of the things being said there now—and lauded—that have NOTHING to do with reality. In many areas, the truth seeker doesn’t stand a chance. But, standing fast for the TRUTH and HONESTY and against those who would use MY experience as a step stool for pumping their uncredentialled and inexperienced ego, to impress the newbie and non-English speaker, I am not welcome there.

Thomas Jefferson said: “Honesty is the first chapter in the book of wisdom.”

If he were alive today, he would probably change that to: “Standing fast for honesty comes at a very high price, especially when the whiners from the politically correct side of the house get involved.”

After the 1938 Munich Conference, Prime Minister Neville Chamberlain stepped out of a small plane, shock a piece of paper in the air, and told his people: “Mister Hitler does not want war.”

That idiotic stance came about two years before “Mr. Hitler” started raining bombs on London and cost the world countless lives. In addition, it could be argued that if the world had been paying attention to Ed Murrow and Bill Shirer (with boots on the ground and inventing broadcast journalism) the war in Europe—and perhaps the world—could have been avoided.

We are all ignorant in many ways and that’s just the cost of being human. But, when it metastases into apathetic or malicious stupidity … it’s terminal and very contagious. The truth is not always pleasant; it is, however, always the truth.:cat:

Bill

Gilmore Girl said:

For me the benefit of larger exit pupil is viewing comfort with glasses and not so much the extra brightness.
But, I have to say on days like today which was gray and drizzling the 7x42 helps. Despite the rain I still saw some warblers, vireos and lots of fall sparrows.
If I didn't wear glasses I'd most likely use a 32mm as primary bino.

Click to expand...

I agree with you on exit pupil. But I find about 5mm the optimum. Anything above creates either lower magnification which I don't care for or a bigger aperture and more weight. I can handle 4mm but it is just a little more finicky unless you have IS which helps.

Re: variation in exit pupils. The diagram here from an earlier study of over 1,000 people would seem to demonstrate significant variation rather than merely an outlier or two stretching the range.

My only point is that while the trend is obvious with age, the variation is significant. This may be some small part of why different people have different preferences in binoculars

Alan

P.S. I am not proselytizing for any particular binocular nor exit pupil, I use a wide range. I was just trying to inject a bit of actual data into the discussion.

If you think you have a bigger pupil diameter than is normal for your age try comparing a couple binoculars with different exit pupil sizes like a 5mm and a 7mm at low light. It will probably surprise you. If you are over 50 you probably won't see any difference.

The definition of range in Statistics is:

"Range (statistics) The difference between the lowest and highest values. In {4, 6, 9, 3, 7} the lowest value is 3, and the highest is 9, so the range is 9 − 3 = 6. Range can also mean all the output values of a function."

So in that study you could have ONE person with a 7.5mm pupil diameter out of the total 1,000 people so it really means nothing.

Has anyone mentioned the one and only disadvantage I can determine with a 7mm exit pupil/large in diameter ocular lenses, as in the ability of early morning or late evening low on the horizon light to enter the ocular from behind one's viewing of a woodland in deepest shadow only to be treated to the bino users equivalent of the Northern Lights?

Clearly a perfectly sealed eye cup would cure this but I doubt that will be achived with most bins as they come from the factory.

LGM

Loud Green Man said:

Has anyone mentioned the one and only disadvantage I can determine with a 7mm exit pupil/large in diameter ocular lenses, as in the ability of early morning or late evening low on the horizon light to enter the ocular from behind one's viewing of a woodland in deepest shadow only to be treated to the bino users equivalent of the Northern Lights?

Clearly a perfectly sealed eye cup would cure this but I doubt that will be achived with most bins as they come from the factory.

LGM

Click to expand...

I agree with the Northern Lights syndrome with 7mm exit pupils. The other big disadvantage is you usually have to have either less magnification or a bigger bulkier binocular. That is why I think 5mm is best and if you need a smaller lighter binocular 4mm can work.

[email protected] said:

If you think you have a bigger pupil diameter than is normal for your age try comparing a couple binoculars with different exit pupil sizes like a 5mm and a 7mm at low light. It will probably surprise you. If you are over 50 you probably won't see any difference.

The definition of range in Statistics is:

"Range (statistics) The difference between the lowest and highest values. In {4, 6, 9, 3, 7} the lowest value is 3, and the highest is 9, so the range is 9 − 3 = 6. Range can also mean all the output values of a function."

So in that study you could have ONE person with a 7.5mm pupil diameter out of the total 1,000 people so it really means nothing.

Click to expand...

[email protected] said:

I agree with you on exit pupil. But I find about 5mm the optimum. Anything above creates either lower magnification which I don't care for or a bigger aperture and more weight. I can handle 4mm but it is just a little more finicky unless you have IS which helps.

Click to expand...

[email protected] said:

I agree with the Northern Lights syndrome with 7mm exit pupils. The other big disadvantage is you usually have to have either less magnification or a bigger bulkier binocular. That is why I think 5mm is best and if you need a smaller lighter binocular 4mm can work.

Click to expand...

But Dennis - what about the r-squared values?? ||



Chosun :gh:

The purpose of a rigorous statistical analysis is so people don't base conclusions on such things as range.