Chosun Juan
Given to Fly
Swarovski SLC 10x56 is clearly better.
Chosun 🙅
Chosun 🙅
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What is more important transmission or exit pupil size as we age? (2 Viewers)
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Hello. With Habicht 10x40W and EL 10x50FP, I can say that EL is noticeably brighter for me in almost all use cases. I am 46 years old, but I did not measure how much my pupils can expand.
A 10x50 has about 56% more "light gathering" area compared to a 10x40. Since the magnifications are the same, the percentages apply to the areas of exit pupils and objecives:
ratio exit pupils area [%] = d1^2 / d2^2 * 100% = 5^2 / 4^2 * 100% ~ 156%
Also, the eye pupils of most old people will reach 5 mm diameter. The difference in transmission values according post #1 (I would look at twilight values) is only 95% - 88% = 7%, ratio = 95/88 * 100% ~ 108%, difference = 8%. So take the 10x50. For interested readers with mathematical knowledge, I will write a longer article on how to calculate using the Merlitz-document (Berek-formula), taking into account the ambient brightness, magnification and transmission - and make a nice diagram. Santa Claus whispered ideas to me tonight.
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Gijs van Ginkel
Well-known member
The question posed as title of this thread can not be answered directly, since the eyes differ quite a bit between ageing persons . In general there are two phenomena that affect the aging eye:
-1- Maximum pupil size is generally decreasing with increasing age (but the amount differs between different persons)
-2- Ageing eyes often suffer of yellowing of the eye lens, making higher transmission of binoculars less effective.
The only way one can find out is to try different binoculars at different light levels.
Gijs van Ginkel
-1- Maximum pupil size is generally decreasing with increasing age (but the amount differs between different persons)
-2- Ageing eyes often suffer of yellowing of the eye lens, making higher transmission of binoculars less effective.
The only way one can find out is to try different binoculars at different light levels.
Gijs van Ginkel
A) Why?
B) Why repeated?
C) What is "clearly better"? Only for you or also for others, for Dennis?
D) Look at page 6, figure 6: http://www.holgermerlitz.de/bino_performance/bino_performance.pdf
But what is, when the older human has shakes, jitters or weak arm muscles? What is "clearly better? Is a 10x56 always, for all people, for me, for Dennis "clearly better" than 8x56 or 10x50 or 8x50 in twilight? Not that Dennis not recognizes the lion or hungry cannibal just when he had too often to put down the too heavy, trembling binoculars ... clearly better for hungry lions and cannibals ... but for Dennis? ;-)
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Maybe better but brighter maybe not. Has anybody ever compared an SLC 10x56 to an HT 10x54 for brightness?
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Thanks! That is a good comparison. Two top binoculars with different apertures and transmissions. Probably a 10 mm aperture advantage is hard to overcome even by a high transmission binocular like the Habicht 10x40W. Excellent Post!
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That would be great! That is what I am looking for. Thanks!
That is true but if you know your pupil size and the yellowing of the eye lens is what causes us to need more light as we get older wouldn't a higher transmission binocular still be beneficial?
Gijs van Ginkel
Well-known member
Dennis, post 30,
Yes, if you know your maximum pupil size you can then decide for a binocular with appropriate exit pupil and high maximum transmission.
Nice Christmas puzzle and in the meantime I wish you a MERRRY CHRISTMAS AND A HAPPY NEW YEAR with many new binoculars to discover.
Gijs van Ginkel
Yes, if you know your maximum pupil size you can then decide for a binocular with appropriate exit pupil and high maximum transmission.
Nice Christmas puzzle and in the meantime I wish you a MERRRY CHRISTMAS AND A HAPPY NEW YEAR with many new binoculars to discover.
Gijs van Ginkel
Just finished studying the document by Dr. Merlitz that @Sterngucker thankfully linked. I found out that the transmission is taken into account in the results. The curves include an assumed transmission of 90%. At my area ratio calculation at post #22, we found that the lens diameters (40 versus 50 mm) sensibly considered in large differences has the most effect in twilight than the small transmission differences of modern (and expensive) binoculars. This is also shown by the diagrams Fig. 5 (page 5) and Fig. 6 (page 6) in the Merlitz paper. You should have a close look at them, that is enough for a theoretical estimation. No further work is necessary, Dr. Merlitz was diligent and is clever. With the computation of the curve sheaf for diagram Fig. 6 (page 6) he has also calculated for older observers.
If you don't fully understand the mathematics - the curve arrays of the aforementioned diagrams are understandable! If I were you, I would also read the text to know the limitations and assumptions of the theoretical considerations.
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I received the Kite Lynx +10x50, and it had a hair on the inside surface of the objective lens and what was really weird is that the IPD adjustment wasn't quite narrow enough for my eyes. I have never encountered that problem before with all the binoculars I have had. I wasn't honestly over impressed with the build quality of it either for a $1K binocular. It had a label on the front of the focuser knob that looked like a cheap decal. The Kite Lynx + 10x50 was pretty good optically with a big FOV. The Kite 16x42 APC Stabilizer binocular I bought developed problems right away with the stabilization system, and it had glare issues so both Kites went back to Belgium. I am not to impressed with Kites at this point although the dealer was excellent. I told him to send me some Belgium Chocolates. I ordered a Fujinon FMTR-SX 10x50 for my handheld astronomy binocular. Sometimes I look at the night sky when it is clear outside.
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Thanks! Merry Christmas to you too and Stay Safe! Hopefully a vaccine is on the way for this COVID virus. I am getting bored with staying home! My wife and I are getting on each other's nerves!
Omid
Well-known member
You are most welcome! I am glad at least one person found my scientific explanations useful. Interestingly, the facts I presented were completely ignored just a few posts down (post # 23) where Jessie went back to the false notion of equating geometric area of the exit pupil as indicative of brightness. Even more interestingly, the original poster loved those false calculations and happily announced that he has found what he was looking for (post # 29)!!! This is all very beautiful and entertaining
I'll copy my post into my own thread New Horizons II and let it stay there for future reference.
@ Gijs (post #25): You pointed to a very important fact about human eye as we age: The eye lens looses transmission, gets yellowish and also develops dark patches which eventually turn into a Cataract.
-Omid
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Omid, I am glad to have contributed to your entertainment. I did not ignore your post but read it with interest and thanked you with a "like". I have dispassionately calculated an area ratio from 2 exit pupils, "light gathering" intentional in quotes. From the beginning I pointed to the German Wikipedia article on telescope performance, which is obviously based on the Merlitz paper or written by Dr. Merlitz himself. I was only aware of the Wikipedia article, not the entire Merlitz paper. Anyway, this makes the problem of the OP mathematically more or less comprehensible. Sometimes in life, however, rules of thumb, simplifications, quick simple approximations are needed. These have limits, of course. The Merlitz paper considers many kinds of ambient light and thus perceptible reflections of light from observation objects. That I have taken from your contribution that only the reflected light contributes to the perception. Nevertheless, only can be reflected what also "irradiates". There is already a dependency or a direct connection/correlation. So an explicit thank you for your contribution! Best regards. Jessie
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Sterngucker
Well-known member
Thanks for pointing me at the New Horizons II thread. Engrossing.You are most welcome! I am glad at least one person found my scientific explanations useful. Interestingly, the facts I presented were completely ignored just a few posts down (post # 23) where Jessie went back to the false notion of equating geometric area of the exit pupil as indicative of brightness. Even more interestingly, the original poster loved those false calculations and happily announced that he has found what he was looking for (post # 29)!!! This is all very beautiful and entertaining
I'll copy my post into my own thread New Horizons II and let it stay there for future reference.
@ Gijs (post #25): You pointed to a very important fact about human eye as we age: The eye lens looses transmission, gets yellowish and also develops dark patches which eventually turn into a Cataract.
-Omid
