I agree. I explained that in post 19. Those values are just averages.
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Allbinos.com review - New Swarovski CL Companion 8x30 B (2 Viewers)
- Thread starter Ontario
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Dennis,
Where on earth did you get an average of 4mm from? I've probably looked at something like a dozen studies of pupil diameter and age and nothing came close to that. The results do vary, mostly depending on the level of light used for testing and the time allowed for the eye to adapt. The results I've seen gave an average between 5 and 5.8mm at the age of 60, but none that I recall, actually attempted to determine a maximum diameter, which presumably would push the averages a little higher.
Attached are screen shots from just a couple of those studies.
Obviously age does take a toll on our eyesight, but don't put us in the grave just yet. I'm over sixty myself and quite aware my eyes are not what they once were, but I still get full value out of a 10x56 and the other visual metrics aren't too bad either.
David
Attachments
Re. Post 15.
According to this my scotopic? pupil should be less than 3.0mm, as I am off the chart.
With the curtains drawn in daylight, where I can still see red, blue and brown objects, although brown isn't I suppose a colour, my pupil is 4.5mm.
At night I seem to use the whole of the Swift Audubon 8.5x44 pupil, about 5.2mm.
I had a fortuitous out of focus image that enabled me to estimate the diameter of an occlusion? in one eye as 0.36mm, with a considerably smaller linear offshoot. This is off centre, so does not affect things much, although I note a loss of fine resolution. It means I can use 0.5mm exit pupils in this eye, but still 0.3mm in my better eye.
The poorer eye, when rested is now 20/20, the better eye 20/16.
Five years ago both were 20/15.
A colleague measured his pupil as 7.0mm at age 65. However, another colleague measured 3.0mm at age 70. I recommended Canon IS binoculars, say 10x30, for the latter or Russian 12x40, 20x60 binoculars
According to this my scotopic? pupil should be less than 3.0mm, as I am off the chart.
With the curtains drawn in daylight, where I can still see red, blue and brown objects, although brown isn't I suppose a colour, my pupil is 4.5mm.
At night I seem to use the whole of the Swift Audubon 8.5x44 pupil, about 5.2mm.
I had a fortuitous out of focus image that enabled me to estimate the diameter of an occlusion? in one eye as 0.36mm, with a considerably smaller linear offshoot. This is off centre, so does not affect things much, although I note a loss of fine resolution. It means I can use 0.5mm exit pupils in this eye, but still 0.3mm in my better eye.
The poorer eye, when rested is now 20/20, the better eye 20/16.
Five years ago both were 20/15.
A colleague measured his pupil as 7.0mm at age 65. However, another colleague measured 3.0mm at age 70. I recommended Canon IS binoculars, say 10x30, for the latter or Russian 12x40, 20x60 binoculars
I found the chart on a Google search. https://www.google.com/search?q=eff...NoQ9QEwCXoECAkQBA#imgrc=8EgX1jHV2AgPQM:&vet=1. Also, down below there is a link for the article which the chart is based on on diminishing pupil size with age and the research behind it. I think everybody is different as far as how much age affects your pupil size. The pupils CERTAINLY get smaller as you get older. How much probably depends on your genetics. I know personally I don't benefit that much any more from a 42mm in the kind of birding I do so for me so it is not worth it to lug around the bigger, heavier binocular but I am over 65. I noticed the change in the last couple of years so my fall off in pupil size has been sudden. IMO The benefit of a bigger aperture certainly decreases as we get older especially for brightness. You still have the advantage of easier eye placement with the bigger exit pupil though. What is interesting is they have found a correlation between pupil size and intelligence. So your bigger pupils could be a sign that you are smarter than me! Here is the research study for the chart with the institute and Doctor that did the study. He has practiced for 25 years so he is well qualified.
"INCREASING AGE, DIMINISHING PUPIL SIZE
Studies show that pupil size is largest during adolescence, and decreases with age. In fact, the pupil reaches its peak size under dim light conditions between 11-17 years old[1]. And whether they’re doing homework, Snapchatting, or taking in a new e-book, this age group is spends a ton of time viewing digital devices after dark. In fact, by the time the average American teenager reaches 17 years old, they will have spent 50,000 hours or 1/3 of their life viewing digital screens[2]. That’s a lot of blue light making it to the retina.
Senile miosis, the decrease in pupil size as we get older, has been attributed to both muscle atrophy, as well as nerve innervation changes along both the parasympathetic (pupillary constriction) and sympathetic (pupillary dilation) pathways[3]. As the following graph shows, the change in pupil size with age is significant[4].
Change in pupil size with age
Pupil size in light (photopic) and dark (scotopic) conditions changes significantly with age. From age 20 to 70, photopic size changes by 2.5 mm, and scotopic size changes by 5.0 mm. Source: NOVEL - Moran Eye Center
Interestingly, the drop in retinal luminance with age is most prominent in the 400-500nm range as shown in the graph below[5]. While this may be a natural protective measure for older eyes, young eyes are vulnerable. In fact, due to changes in the crystalline lens and pupil size, a typical 20 year old receives 3x the retinal luminance of a 60 year old[6].
Pupil-weighted spectral retinal illumination chart
Age-related losses in retinal illumination due to decreasing crystalline lens light transmission and pupil area. The percentage of loss per decade is reasonably uniform and most prominent at shorter violet (400–440 nm) and blue (440–500 nm) wavelengths. Image: International Journal of Medical Science
And let’s not forget our children are getting an amplified dose of blue light intensity from viewing devices closer up. So young eyes are receiving more blue light on the retina at a significantly greater intensity.
The question that remains to be answered is whether or not that increased exposure will lead to retinal damage over time?
In part three of the series, we’ll discuss the density of a child’s crystalline lens, and how that can put them at greater risk of blue light exposure.
READ PART 3 OF THE SERIES
The Evolving Science of Blue Light White Paper
About the author: Dr. Gary Morgan has been in private practice for 25 years in Arizona, with an emphasis on the care of patients at risk of, or with AMD. An advocate for innovation, he serves in a technical advisory capacity to ophthalmic industry enterprises focusing on spectacle lenses, nutraceuticals, and telemedicine that are intent on lessening the effects of AMD and blue light.
Picture
Loewenfeld IE: “Simple, central” anisocoria: A common condition, seldom recognized. Trans Am Acad Ophthalmol, 1977; 82:832–839.
Source: http://vspblog.com/blue-light-infographic/
Richdale, K. Ocular and Refractive Considerations for the Aging Eye, Contact Lens Spectrum, February 2009
Benjamin W, Borish I. Borish's clinical refraction. Philadelphia: W.B. Saunders; 2006.
Bonmati-Carrion M et al. Protecting the Melatonin Rhythm through Circadian Healthy Light Exposure. Int. J. Mol. Sci. 2014, 15(12), 23448-23500
Lighting Research Center, Rensselaer Polytechnic Institue, Troy NY. http://www.lrc.rpi.edu/programs/lig...art-2-of-4-pupil-size-and-blue-light-exposure
http://blogs.discovermagazine.com/neuroskeptic/2016/11/20/pupil-size-intelligence/#.XNRDZYtKiUk
"INCREASING AGE, DIMINISHING PUPIL SIZE
Studies show that pupil size is largest during adolescence, and decreases with age. In fact, the pupil reaches its peak size under dim light conditions between 11-17 years old[1]. And whether they’re doing homework, Snapchatting, or taking in a new e-book, this age group is spends a ton of time viewing digital devices after dark. In fact, by the time the average American teenager reaches 17 years old, they will have spent 50,000 hours or 1/3 of their life viewing digital screens[2]. That’s a lot of blue light making it to the retina.
Senile miosis, the decrease in pupil size as we get older, has been attributed to both muscle atrophy, as well as nerve innervation changes along both the parasympathetic (pupillary constriction) and sympathetic (pupillary dilation) pathways[3]. As the following graph shows, the change in pupil size with age is significant[4].
Change in pupil size with age
Pupil size in light (photopic) and dark (scotopic) conditions changes significantly with age. From age 20 to 70, photopic size changes by 2.5 mm, and scotopic size changes by 5.0 mm. Source: NOVEL - Moran Eye Center
Interestingly, the drop in retinal luminance with age is most prominent in the 400-500nm range as shown in the graph below[5]. While this may be a natural protective measure for older eyes, young eyes are vulnerable. In fact, due to changes in the crystalline lens and pupil size, a typical 20 year old receives 3x the retinal luminance of a 60 year old[6].
Pupil-weighted spectral retinal illumination chart
Age-related losses in retinal illumination due to decreasing crystalline lens light transmission and pupil area. The percentage of loss per decade is reasonably uniform and most prominent at shorter violet (400–440 nm) and blue (440–500 nm) wavelengths. Image: International Journal of Medical Science
And let’s not forget our children are getting an amplified dose of blue light intensity from viewing devices closer up. So young eyes are receiving more blue light on the retina at a significantly greater intensity.
The question that remains to be answered is whether or not that increased exposure will lead to retinal damage over time?
In part three of the series, we’ll discuss the density of a child’s crystalline lens, and how that can put them at greater risk of blue light exposure.
READ PART 3 OF THE SERIES
The Evolving Science of Blue Light White Paper
About the author: Dr. Gary Morgan has been in private practice for 25 years in Arizona, with an emphasis on the care of patients at risk of, or with AMD. An advocate for innovation, he serves in a technical advisory capacity to ophthalmic industry enterprises focusing on spectacle lenses, nutraceuticals, and telemedicine that are intent on lessening the effects of AMD and blue light.
Picture
Loewenfeld IE: “Simple, central” anisocoria: A common condition, seldom recognized. Trans Am Acad Ophthalmol, 1977; 82:832–839.
Source: http://vspblog.com/blue-light-infographic/
Richdale, K. Ocular and Refractive Considerations for the Aging Eye, Contact Lens Spectrum, February 2009
Benjamin W, Borish I. Borish's clinical refraction. Philadelphia: W.B. Saunders; 2006.
Bonmati-Carrion M et al. Protecting the Melatonin Rhythm through Circadian Healthy Light Exposure. Int. J. Mol. Sci. 2014, 15(12), 23448-23500
Lighting Research Center, Rensselaer Polytechnic Institue, Troy NY. http://www.lrc.rpi.edu/programs/lig...art-2-of-4-pupil-size-and-blue-light-exposure
http://blogs.discovermagazine.com/neuroskeptic/2016/11/20/pupil-size-intelligence/#.XNRDZYtKiUk
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Thanks Dennis for the short paper above.
There are many different studies.
I think I have read that pupil size is a maximum around 20 years old, but I could be mistaken.
But I don't think that 11 to 17 or 20 year olds are as smart as they think.
I have seen quite a lot of cases on T.V. and in movies where pupils have reached 9mm in younger actors.
Apparently, at this size their eyes are very poor regarding resolution.
I won't give names, but some actors also seem to have tiny pupils, and I have seen various explanations for this.
Blue light is bad for humans and animals.
Blue LEDs are bad. But I think that the number of LEDs that have been made might be getting on for a trillion?
Light pollution is terribly bad, affecting circadian effects.
We are losing numerous species, and this is part of the problem.
Near blue light was considered most damaging.
For me, tiredness of my eyes is the limiting factor rather than pupil size, but I definitely see a brighter image at night with 5.2mm exit pupil rather than 4.0mm.
But I use Canon 18x50, 2.8mm.
Docter 10x25, 2.5mm.
8x32 BA, 4.0mm.
Swift HR/5 8.5x44, 5.2mm.
Telescopes, down to 0.3mm.
And anything else, really.
I have lost about one magnitude in the faintest stars that I can see from say 20 years old.
That is a 2.5 times loss.
However, I saw fainter stars at say 25 to 30 years of age than when 15 to 20 years, because I became a more experienced observer.
Even in my late forties I saw 15 or 16 Pleiads from La Palma at 7,900 ft on a night which the locals said was not very good. Without glasses.
Also 13 at sea level from a town by the sea. The 12th and 13th Pleiads are about magnitude 6.2 and 6.4.
The 8th Pleiad is magnitude 5.5.
Pleione is variable magnitude 4.8 to 5.5 and I used to see this variability easily with unaided eyes.
So 7 Pleiads are pretty easy at a dark site.
I easily saw 11 Pleiads next to the Harvard public 9.5 inch refractor when I showed a group the night sky, and always 11 from town at home when young.
The light pollution is so bad here now, I can hardly see any stars.
Regards,
B.
There are many different studies.
I think I have read that pupil size is a maximum around 20 years old, but I could be mistaken.
But I don't think that 11 to 17 or 20 year olds are as smart as they think.
I have seen quite a lot of cases on T.V. and in movies where pupils have reached 9mm in younger actors.
Apparently, at this size their eyes are very poor regarding resolution.
I won't give names, but some actors also seem to have tiny pupils, and I have seen various explanations for this.
Blue light is bad for humans and animals.
Blue LEDs are bad. But I think that the number of LEDs that have been made might be getting on for a trillion?
Light pollution is terribly bad, affecting circadian effects.
We are losing numerous species, and this is part of the problem.
Near blue light was considered most damaging.
For me, tiredness of my eyes is the limiting factor rather than pupil size, but I definitely see a brighter image at night with 5.2mm exit pupil rather than 4.0mm.
But I use Canon 18x50, 2.8mm.
Docter 10x25, 2.5mm.
8x32 BA, 4.0mm.
Swift HR/5 8.5x44, 5.2mm.
Telescopes, down to 0.3mm.
And anything else, really.
I have lost about one magnitude in the faintest stars that I can see from say 20 years old.
That is a 2.5 times loss.
However, I saw fainter stars at say 25 to 30 years of age than when 15 to 20 years, because I became a more experienced observer.
Even in my late forties I saw 15 or 16 Pleiads from La Palma at 7,900 ft on a night which the locals said was not very good. Without glasses.
Also 13 at sea level from a town by the sea. The 12th and 13th Pleiads are about magnitude 6.2 and 6.4.
The 8th Pleiad is magnitude 5.5.
Pleione is variable magnitude 4.8 to 5.5 and I used to see this variability easily with unaided eyes.
So 7 Pleiads are pretty easy at a dark site.
I easily saw 11 Pleiads next to the Harvard public 9.5 inch refractor when I showed a group the night sky, and always 11 from town at home when young.
The light pollution is so bad here now, I can hardly see any stars.
Regards,
B.
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What is really interesting is you need three times as much light to see clearly at 60 than you did at 20. When dark adapted the 20 year old receives 16 times more light than the 80 year old. That is scary!
https://seniordriving.aaa.com/understanding-mind-body-changes/vision/light-requirements/
https://seniordriving.aaa.com/understanding-mind-body-changes/vision/light-requirements/
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Conndomat
United States of Europe
No...https://www.nikon.de/de_DE/product/sport-optics/binoculars/edg/edg-7x42#tech_specs
No...https://www.nikon.de/de_DE/product/sport-optics/binoculars/edg/edg-10x32#tech_specs
The values determined by Nikon, here again the distortion was considered, the only correct way to determine the AFOV.
Andreas
As quoted by Henry Link from a thread on AFOV. The thread link is at the bottom.
"Nikon has just adopted the method described here for AFOV specifications:
http://www.ave.nikon.co.jp/bi_e/prod.../chart_001.jpg
Others may follow (or already have done) in order to conform to the ISO standard. In the meantime Nikon specs will be confusing when compared to other manufacturers. I think it's probably best to continue to compare approximate apparent fields by multiplying the real angular field by the magnification like it's always been done in marketing materials."
https://www.birdforum.net/showthread.php?t=109343
"Nikon has just adopted the method described here for AFOV specifications:
http://www.ave.nikon.co.jp/bi_e/prod.../chart_001.jpg
Others may follow (or already have done) in order to conform to the ISO standard. In the meantime Nikon specs will be confusing when compared to other manufacturers. I think it's probably best to continue to compare approximate apparent fields by multiplying the real angular field by the magnification like it's always been done in marketing materials."
https://www.birdforum.net/showthread.php?t=109343
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Or headlights...
henry link
Well-known member
As quoted by Henry Link from a thread on AFOV. The thread link is at the bottom.
"Nikon has just adopted the method described here for AFOV specifications:
http://www.ave.nikon.co.jp/bi_e/prod.../chart_001.jpg
Others may follow (or already have done) in order to conform to the ISO standard. In the meantime Nikon specs will be confusing when compared to other manufacturers. I think it's probably best to continue to compare approximate apparent fields by multiplying the real angular field by the magnification like it's always been done in marketing materials."
https://www.birdforum.net/showthread.php?t=109343
Dennis,
I wouldn't make that last statement now. When that thread appeared back in 2008 I didn't yet realize that the true AFOV, including distortion, can be measured pretty easily with the binocular mounted on a panoramic tripod head with a degree scale. What's the point in advocating for either the ISO or the simple calculation when both are likely to be wrong?
If you look at the current AFOV specs from Swarovski and Zeiss you'll find that they don't match either calculation. That means they're either accurately calculated by including known amounts of distortion or they're measured. Hopefully everyone else will eventually do the same
"Nikon has just adopted the method described here for AFOV specifications:
http://www.ave.nikon.co.jp/bi_e/prod.../chart_001.jpg
Others may follow (or already have done) in order to conform to the ISO standard. In the meantime Nikon specs will be confusing when compared to other manufacturers. I think it's probably best to continue to compare approximate apparent fields by multiplying the real angular field by the magnification like it's always been done in marketing materials."
https://www.birdforum.net/showthread.php?t=109343
Dennis,
I wouldn't make that last statement now. When that thread appeared back in 2008 I didn't yet realize that the true AFOV, including distortion, can be measured pretty easily with the binocular mounted on a panoramic tripod head with a degree scale. What's the point in advocating for either the ISO or the simple calculation when both are likely to be wrong?
If you look at the current AFOV specs from Swarovski and Zeiss you'll find that they don't match either calculation. That means they're either accurately calculated by including known amounts of distortion or they're measured. Hopefully everyone else will eventually do the same
You're correct. I was reading about your measurement method over at Cloudy Nights. I believe it was Dr. Ed that was explaining it. I have used the simple calculation method because at least it is relative to every binocular. That is good to know that Swarovski and Zeiss are using the more accurate method of determining AFOV. It would be nice if the rest of the manufacturers would do the same because it makes it impossible to compare binoculars across the board. Thanks for the update on the methodology.
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Conndomat
United States of Europe
:t:
Quote Holger Merlitz ...
"The question of why manufacturers calculate their visual angles with inaccurate formulas (rather than simply specifying the laboratory values), I have often asked myself and never received a convincing answer.As long as you still consistently used the angle condition, the subjective visual angle was usually overestimated - it So it seems obvious that marketing could live well with this approximation. "
https://www.juelich-bonn.com/jForum/read.php?9,443747
Only in German...
Andreas
It would be nice like Henry said if all the manufacturers would use the same method of figuring AFOV. Either by measuring it or specifying lab values. Nikon's ISO method is very confusing. At least Zeiss and Swarovski are doing it correctly and are consistent so you can compare AFOV values.:t:
Quote Holger Merlitz ...
"The question of why manufacturers calculate their visual angles with inaccurate formulas (rather than simply specifying the laboratory values), I have often asked myself and never received a convincing answer.As long as you still consistently used the angle condition, the subjective visual angle was usually overestimated - it So it seems obvious that marketing could live well with this approximation. "
https://www.juelich-bonn.com/jForum/read.php?9,443747
Only in German...
Andreas
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SeldomPerched
Well-known member
This 63 year old is hoping that his weight training will help keep the 8x56 FL steady for a few years more .... I made the mistake of using it the other day, and immediately wanted to throw away all the smaller glass. Boy, it's that good!
Tom
Conndomat
United States of Europe
:t:
Hi Dennis,
Zeiss is only correct for the SF models, the Conquest are not correct again!
Only Swarovski determines the right AFOV for his entire range of binoculars.
Measuring yourself is the only way for the other manufacturers to determine the correct AFOV.
Andreas
elkcub
Silicon Valley, California
How do they accomplish this, and how do we know it's the "right" AFOV?
I'm interested.
Ed
Conndomat
United States of Europe
Hallo Ed,
The best way to measure the AFOV is to mount the binoculars horizontally on a tripod, set the focus to infinity, and direct the eyepieces to a distant edge of the building. By a LENS !!! If you look at it, note the degree measurements on the panoramic head where the edge of a building just disappears to the left and right. The AFOV is the difference between the two readings. At distances of about 50 m, the parallax error, caused by the tilt of the eyepiece, is negligible.With this method you can check all values of Swarovski and the Zeiss SF. All measurements comply with the manufacturer's specifications!
The values with the simple method degree x magnification differ from the measured values up to 6 degrees!
Andreas
Edit:In the case of ambiguity, I hope that Henry Link can explain the measurement method more clearly and in correct English!
The best way to measure the AFOV is to mount the binoculars horizontally on a tripod, set the focus to infinity, and direct the eyepieces to a distant edge of the building. By a LENS !!! If you look at it, note the degree measurements on the panoramic head where the edge of a building just disappears to the left and right. The AFOV is the difference between the two readings. At distances of about 50 m, the parallax error, caused by the tilt of the eyepiece, is negligible.With this method you can check all values of Swarovski and the Zeiss SF. All measurements comply with the manufacturer's specifications!
The values with the simple method degree x magnification differ from the measured values up to 6 degrees!
Andreas
Edit:In the case of ambiguity, I hope that Henry Link can explain the measurement method more clearly and in correct English!
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Figures!
In the notes for the 2015 revision of ISO14132-1 it says "in the absence of distortion" their formula will give the image angular field of view. Models with a flattened field of view, like the Nikon EDG, Swarovski ELFP and Zeiss SF have angular distortion. Does that mean their values using the ISO method are erroneous as the angle is compressed? Does it also mean that where there is no flattening, that the linear and angular method should give the same result?
Just food for thought.
I'm not really bothered which method manufacturers use, providing the values are accurate and they tell us which one. It seems to me that the linear is probably the easiest to understand as it tells you how much real estate you can actually see.
I've tried using the real (not the published) ER values and the diameter of the eyepiece lens to estimate the AFoV as a check on the published values. It's been quite revealing.
David
Just food for thought.
I'm not really bothered which method manufacturers use, providing the values are accurate and they tell us which one. It seems to me that the linear is probably the easiest to understand as it tells you how much real estate you can actually see.
I've tried using the real (not the published) ER values and the diameter of the eyepiece lens to estimate the AFoV as a check on the published values. It's been quite revealing.
David
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