What is more important transmission or exit pupil size as we age? (2 Viewers)

[sidpost]

Sidpost,

Now that you have made up your mind - time to put out some cash, because if you are looking for a low priced HT 10X54, you could be 6 feet under by then.

Andy W.

A fair point Andy!

In Europe, I have seen gently used models sell for ~$1500USD. If they would ship to the USA, they would be on their way right now! With the Christmas and COVID craziness, I understand their reluctance to try to ship them internationally. I actually tried to buy a pair in London but, they won't ship outside of the UK which is somewhat understandable with Brexit looming and all the border uncertainties. I prefer Schiphol to UK airport options but, that would make an easy shopping detour with an easy hop across the channel. I even tried to get them to ship to Cologne, DE but no luck with that option. If my friend ever goes to London, I might see if he can swing by the shop assuming I haven't already purchased by then.

In the USA, they are much harder to find though, I have some identified to purchase after the current shipping problems diminish. With only ~$300USD difference between used (in the USA) and new, I'm 99% sure some new ones are headed my way the first part of January assuming shipping becomes less chaotic.

If travel restrictions weren't so problematic with COVID lockdowns, I would be really tempted to grab a Eurail pass and go used binocular shopping in Western Europe! Putting my own hands and eyes on some Habicht options and a pair of Zeiss 15x60 B/GA's to verify my own personal eye relief needs with my glasses and facial structure would be awesome!

 

[dries1]

Sidpost, the mail delivery business now is getting crushed world wide, and I have seen major delays for the last month here on the east coast. I have shut down all deliveries until after the new year. Additionally some optical repair houses have done this as well.
Hope you get a good/fair price on those Hts.

Andy W.

 

[sidpost]

Sidpost, the mail delivery business now is getting crushed world wide, and I have seen major delays for the last month here on the east coast. I have shut down all deliveries until after the new year. Additionally some optical repair houses have done this as well.
Hope you get a good/fair price on those Hts.

Andy W.

I have had two recent failed deliveries refunded by Amazon after 30 days. They both did show up eventually. Like you, at this point, if it is not trackable shipping, I'm not buying - PERIOD!

I did have a Sugimoto cleaver and separately a different shipment of two Gyuto from Japan which arrived safely and timely thanks to DHL trackable shipping. Normally, Japanese postal EMS is a two-day delivery at a very modest price but, with COVID that is not an option today.

Right now, I'm hopeful mid-January gets back to normal though a >$2K pair of binoculars shipped 2-day FedEx or UPS isn't unreasonable within the Continental USA.

I am considering rebuilding my KLX-250S or buying a new small dual-sport motorcycle. On my trip to Dallas, I checked out a couple of Yamaha dealers to possibly buy a new WR-250R with fuel injection instead but, all they would do is take a $1,000 deposit and order one for delivery at some point in the future. The last time I did that, I lost my money on a sound suppressor purchase when the dealer closed their shop and left town thanks to the long NFA approval process even though I already owned other NFA items (this was a suppressor for a submachine gun). I did find an in-stock Vespa in my preferred color though which is likely going to be my "Christmas" present to myself! No worries there as I have already put my "butt print" on the seat!

 

[Dennis Mau]

A fair point Andy!

In Europe, I have seen gently used models sell for ~$1500USD. If they would ship to the USA, they would be on their way right now! With the Christmas and COVID craziness, I understand their reluctance to try to ship them internationally. I actually tried to buy a pair in London but, they won't ship outside of the UK which is somewhat understandable with Brexit looming and all the border uncertainties. I prefer Schiphol to UK airport options but, that would make an easy shopping detour with an easy hop across the channel. I even tried to get them to ship to Cologne, DE but no luck with that option. If my friend ever goes to London, I might see if he can swing by the shop assuming I haven't already purchased by then.

In the USA, they are much harder to find though, I have some identified to purchase after the current shipping problems diminish. With only ~$300USD difference between used (in the USA) and new, I'm 99% sure some new ones are headed my way the first part of January assuming shipping becomes less chaotic.

If travel restrictions weren't so problematic with COVID lockdowns, I would be really tempted to grab a Eurail pass and go used binocular shopping in Western Europe! Putting my own hands and eyes on some Habicht options and a pair of Zeiss 15x60 B/GA's to verify my own personal eye relief needs with my glasses and facial structure would be awesome!

Here is our friend from Optica Exotica doing a review on the Zeiss HT 10x54. He does say they are bright, but he doesn't like the fall off at the edges.

 

[Dennis Mau]

Simple mathematics.
fn (mag*tr%*Obj.dia)

Weight and shake are very much also a user dependent factor.

5+ mm pupil dilation is quite typical even for folks in their 8th decade. There was some nice data floating around somewhere way back when - did Ed present ?

I see you've now ordered


Better order the superior 93%tr Swarovski SLC 10x56 for comparison too !

Don't bother with the Zeiss HT 10x54 - it's not in the running - maths.

For handheld viewing, good IS is going to trump a lot of minor differences in those other factors.

I think you better try and ferret out a 12x60 IS somewhere .... 😉



Chosun 🙅

So if we use your equation and plug in the values on the Meopta Meostar 10x50 @ 88% transmission and the Swarosvki Habicht 10x40 @ 95% transmission you get 440 for the Meopta and 380 for the Habicht. So could you say the Meopta will be 14% brighter?

Simple mathematics.
fn (mag*tr%*Obj.dia)

 

[John A Roberts]

FWIW

Roger Vine has tested various large aperture 10x binoculars, including:
• Swarovski EL SV 10x50
• Zeiss HT 10x54 and Conquest HD 10x56, and
• Swarovski SLC 10x56
see at: http://www.scopeviews.co.uk/BinoReviews.htm

And in the SLC review he directly compared it to the two Zeiss models

- - - -

And on CloudyNights there is comparative comment on the 10x50 EL SV vs the Fuji FMTR-SX,
see at: https://www.cloudynights.com/topic/565990-swarovski-el-10x50-vs-fuji-fmtr-sx-10x50/


John

 

[dries1]

I think if he (Optica Exotica) is going to continue to do video reviews, he needs to up grade his audio, I should not hear the noise of the wind while he is speaking, perhaps some Bach/Wagner on low/background would be good. Two, he needs to find other locations than being on a cliff, overlooking the ocean - with high gusty winds, yes nice views, but how about some other venues.
I always get some laughs from his videos however, thanks Dennis, always good to get a good laugh nowadays.

Andy W.

 

[Chosun Juan]

So if we use your equation and plug in the values on the Meopta Meostar 10x50 @ 88% transmission and the Swarosvki Habicht 10x40 @ 95% transmission you get 440 for the Meopta and 380 for the Habicht. So could you say the Meopta will be 14% brighter?

Simple mathematics.
fn (mag*tr%*Obj.dia)

@dennis - No, no, not quite - I said it's a function (fn) of those variables. Area based, not linear. You will have to go to Holger's paper to see how they tie in to available light levels (it's been a while since I read it, so I think it refers to supported bins - taking a further variable for shake out of the equation). I only said those 3 variables because the visual acuity in various light levels pretty much shakes out on magnification lines until it gets quite dark. The magnification correlates visual acuity to those light levels.

It's all charted quite simply. Great work 👍

What you can do pretty accurately for yourself though, for a given magnification is calculate the area (obj or EP) × transmission rate. The difference in your two bins is closer to 44%*

*You would have to pay attention to the EP diameter compared to your dilated pupil diameter under the considered lighting levels. Also, as you said previously, Fov, and field preferences may come into it for you too.

Just be aware that the transmission figure quoted is the daylight figure, and when light levels drop into the mesopic region, then the 'night' transmission levels take over. (Actually the whole curve counts as an integrated value). These day 555nm, and night 507nm, values are often quoted, or able to be read off a chart so you can compare.

It's not quite that simple - but a reasonable guide - there aren't an infinite amount of binoculars available .... 👍

You should also be aware that unless looking at moonless midnight, you might be better off with a very slightly smaller EP and less eyeball aberrations.



Chosun 🙅

 

[sidpost]

Here is our friend from Optica Exotica doing a review on the Zeiss HT 10x54. He does say they are bright, but he doesn't like the fall off at the edges.

First, a microphone baffle to block wind noise would be a good idea that would improve the quality of his YouTube videos a lot.

The images shown are enticing though, images in YouTube like that pale in comparison to reality once you have the 'in-person' experience.

To me, he seems overly critical but, that is fair in a set of binoculars this expensive. While I don't know him at all, I sensed some bias in his review. Most of what he stated negatively in his review in terms of edge softness was already well documented so, no surprises there. The edge distortion video seemed to be specifically exaggerated but, again at this price point I guess it is a reasonable concern that it isn't better in this regard. I guess this is the type of issue 'flatners' deal with which might help the HT's but, then you are adding weight which takes away from one of the features of these "big eye" bins.

The "sweet spot" and brightness are attractive to me. Some of those sea views are really nice as well and are encouraging that I'm on the right track for what I want. His comments regarding handling are spot on as well with my expectations.

 

[dries1]

Dennis,

Perhaps spend some time with both the Habicht 10X42 and a Meopta 10X50, say for a period of three weeks to a month with varying viewing conditions. You will get realistic results to what suits your aging eyes.

Andy W.

 

[Jessie-66]

So if we use your equation and plug in the values on the Meopta Meostar 10x50 @ 88% transmission and the Swarosvki Habicht 10x40 @ 95% transmission you get 440 for the Meopta and 380 for the Habicht. So could you say the Meopta will be 14% brighter?

Simple mathematics.
fn (mag*tr%*Obj.dia)

In low-light conditions (moonlight, residual light at night), the resolution gain E is approximated by Köhler and Leinhos [1], [2]:
E ~ D * sqrt T
sqrt ... square root
D ... light effective diameter of the objective lenses in mm
T ... transmission in twilight (~ 510 nm wave length, T in % / 100 %)
More accurate and for wider ranges is the use of Dr. Merlitz's diagrams/nomograms [2]. One can simply read off but the calculation is very complex.
I like quick and dirty rules of thumb's for praxis, therefore Mr. Köhler and Mr. Leinhos (formula 4, page 2) and Dr. Merlitz's diagrams (Fig. 5, page 5 and Fig. 6, page 6) for Mr. Berek's results [2].

I have simplified the formula of Köhler and Leinhaus for the special case twilight (x = 1/4):
E ~ sqrt (m * D / de) * T exp 1/4
m ... magnification
de ... diameter of the eye pupil, I think one can use for twilight 4 ... 5 mm (maximum: exit pupil diameter).
T exp 1/4 is also the mathematical 4th root of the transmission T.

Thus, we now have 2 simple formulas that are practically quick and easy to calculate - in addition to Dr. Merlitz's nomograms for Berek's model.

The well known twilight factor TF does not take transmission into account:
TF = sqrt (m * D)
Correlation with binoculars performance - but without consideration of transmission; please use an online translator:

Dämmerungszahl – Wikipedia

de.wikipedia.org

[1) Merlitz: Performance of binoculars: Berek’s model of target detection

http://www.holgermerlitz.de/bino_performance/bino_performance.pdf

[2] German Wikipedia: Fernrohrleistung (Please use an online translator.)

Fernrohrleistung – Wikipedia

de.wikipedia.org

I leave the calculation for comparison of 2 bins with the ratio E1 / E2 * 100 % to the OP, I am not a primary/basic/elementary school teacher. ;-)

Edit: Text changed and corrected several times.

 

[Dennis Mau]

FWIW

Roger Vine has tested various large aperture 10x binoculars, including:
• Swarovski EL SV 10x50
• Zeiss HT 10x54 and Conquest HD 10x56, and
• Swarovski SLC 10x56
see at: http://www.scopeviews.co.uk/BinoReviews.htm

And in the SLC review he directly compared it to the two Zeiss models

- - - -

And on CloudyNights there is comparative comment on the 10x50 EL SV vs the Fuji FMTR-SX,
see at: https://www.cloudynights.com/topic/565990-swarovski-el-10x50-vs-fuji-fmtr-sx-10x50/


John

Thanks, John. Very helpful! I have read all those reviews, and they are all very good. I disagree with some of the opinions on CloudyNights on the 10x50 EL SV and the Fujinon FMTR-SX 10x50, as far as, astronomical use. I like the Fujinon a little better for the night sky because of its higher transmission and slightly sharper edges on star fields. The EL 10x50 is no doubt a better all around binocular though because of its CF instead of the IF on the Fujinon and its smaller size and lighter weight. The Fujinon is also a third of the price of the EL.

 

[Dennis Mau]

I think if he (Optica Exotica) is going to continue to do video reviews, he needs to up grade his audio, I should not hear the noise of the wind while he is speaking, perhaps some Bach/Wagner on low/background would be good. Two, he needs to find other locations than being on a cliff, overlooking the ocean - with high gusty winds, yes nice views, but how about some other venues.
I always get some laughs from his videos however, thanks Dennis, always good to get a good laugh nowadays.

Andy W.

I know! The guy is funny though, isn't he? He is pretty knowledgeable though concerning binoculars. I share his opinon on Zeiss binoculars. In ways, they are sensational like on-axis resolution but in other ways they don't quite hit the mark especially concerning quality. I expected him to fall off the cliff at anytime! It looks a little dangerous!

 

[Dennis Mau]

@dennis - No, no, not quite - I said it's a function (fn) of those variables. Area based, not linear. You will have to go to Holger's paper to see how they tie in to available light levels (it's been a while since I read it, so I think it refers to supported bins - taking a further variable for shake out of the equation). I only said those 3 variables because the visual acuity in various light levels pretty much shakes out on magnification lines until it gets quite dark. The magnification correlates visual acuity to those light levels.

It's all charted quite simply. Great work 👍

What you can do pretty accurately for yourself though, for a given magnification is calculate the area (obj or EP) × transmission rate. The difference in your two bins is closer to 44%*

*You would have to pay attention to the EP diameter compared to your dilated pupil diameter under the considered lighting levels. Also, as you said previously, Fov, and field preferences may come into it for you too.

Just be aware that the transmission figure quoted is the daylight figure, and when light levels drop into the mesopic region, then the 'night' transmission levels take over. (Actually the whole curve counts as an integrated value). These day 555nm, and night 507nm, values are often quoted, or able to be read off a chart so you can compare.

It's not quite that simple - but a reasonable guide - there aren't an infinite amount of binoculars available .... 👍

You should also be aware that unless looking at moonless midnight, you might be better off with a very slightly smaller EP and less eyeball aberrations.



Chosun 🙅

Good! Nice, Chosun. Great information. The aperture makes way more difference than the transmission. Interesting about the differences in daylight and night transmission. It is something else to consider.

 

[Dennis Mau]

Dennis,

Perhaps spend some time with both the Habicht 10X42 and a Meopta 10X50, say for a period of three weeks to a month with varying viewing conditions. You will get realistic results to what suits your aging eyes.

Andy W.

I actually compared the Habicht 10x40 GA and the Meopta Meostar 10x50 and the Meopta WAS brighter than the Habicht, but I was looking for a binocular for astronomy, so I tried a Fujinon FMTR-SX 10x50 and I found it to be brighter than the Meopta probably because of the higher transmission, and it had much sharper edges which I like for the night sky, so I kept the Fujinon. I think the Fujinon FMTR-SX 10x50 is hard to beat for a hand held astronomy binocular for the price.

 

[Dennis Mau]

In low-light conditions (moonlight, residual light at night), the resolution gain E is approximated by Köhler and Leinhos:
E ~ D * sqrt T
sqrt ... square root
D ... light effective diameter of the objective lenses in mm
T ... transmission in twilight (~ 510 nm wave length, T in % / 100 %)
In twilight, magnification is also taken into account for E. The well known Twilight factor [1] does not include transmission. One can use instead formula 4 (page 2) of the Merlitz paper - with a value of 1/4 for the empirically determined variable x. More accurate and for wider ranges is the use of Dr. Merlitz's diagrams/nomograms. One can simply read off but the calculation is very complex.
I like quick and dirty rules of thumb's for praxis, therefore Mr. Köhler and Mr. Leinhos (formula 4) and Dr. Merlitz's diagrams for Mr. Berek's results.

Edit:
I have now simplified the formula of Köhler and Leinhaus for the special case twilight (x = 1/4):
E ~ sqrt (m * D / de) * T exp 1/4
m ... magnification
de ... diameter of the eye pupil, I think one can use for twilight 4 ... 5 mm (maximum: exit pupil diameter).
T exp 1/4 is also the mathematical 4th root of the transmission T.

Thus, we now have 2 simple formulas that are practically quick and easy to calculate - in addition to Dr. Merlitz's nomograms for Berek's model. I leave the calculation for comparison of 2 bins with the ratio E1 / E2 * 100 % to the OP, I am not a primary/basic/elementary school teacher. ;-)

[1] Twilight factor TF = sqrt (m * D)
Correlation with binoculars performance - but without consideration of transmission; please use an online translator:

Dämmerungszahl – Wikipedia

de.wikipedia.org

I wish you were sitting next to me when I had those math exams in college! I would have copied off your test paper. Nice formulas. Now we have nice formulas that quantifies the relationship between transmission, exit pupil size, magnification and age.

 

[fotbg]

In low-light conditions (moonlight, residual light at night), the resolution gain E is approximated by Köhler and Leinhos:
E ~ D * sqrt T
sqrt ... square root
D ... light effective diameter of the objective lenses in mm
T ... transmission in twilight (~ 510 nm wave length, T in % / 100 %)
In twilight, magnification is also taken into account for E. The well known Twilight factor [1] does not include transmission. One can use instead formula 4 (page 2) of the Merlitz paper - with a value of 1/4 for the empirically determined variable x. More accurate and for wider ranges is the use of Dr. Merlitz's diagrams/nomograms. One can simply read off but the calculation is very complex.
I like quick and dirty rules of thumb's for praxis, therefore Mr. Köhler and Mr. Leinhos (formula 4) and Dr. Merlitz's diagrams for Mr. Berek's results.

Edit:
I have now simplified the formula of Köhler and Leinhaus for the special case twilight (x = 1/4):
E ~ sqrt (m * D / de) * T exp 1/4
m ... magnification
de ... diameter of the eye pupil, I think one can use for twilight 4 ... 5 mm (maximum: exit pupil diameter).
T exp 1/4 is also the mathematical 4th root of the transmission T.

Thus, we now have 2 simple formulas that are practically quick and easy to calculate - in addition to Dr. Merlitz's nomograms for Berek's model. I leave the calculation for comparison of 2 bins with the ratio E1 / E2 * 100 % to the OP, I am not a primary/basic/elementary school teacher. ;-)

[1] Twilight factor TF = sqrt (m * D)
Correlation with binoculars performance - but without consideration of transmission; please use an online translator:

Dämmerungszahl – Wikipedia

de.wikipedia.org

Thanks for providing this. Based on this, it seems changes in magnification and Aperture have the biggest impact on twilight performance with transmission being minor.

 

[Jessie-66]

Thanks for providing this. Based on this, it seems changes in magnification and Aperture have the biggest impact on twilight performance with transmission being minor.

@fotbg: It is the case that the effective objective diameter is included in the resolution gain with exponent 2 compared to the transmission, in night with moonlight or residual light and twilight. The same applies to differences between bins.

@[email protected]:
Everyone has weaknesses, you admit them, you seem honest and helpful to me. And entertaining. I would have let you copy off in tests. Tutoring would be better. ;-)

 

[tenex]

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

You can be quite amusing yourself, as unscientific gaffes in your New Horizons thread showed, or so easily entranced by obscure technical issues that you pay no attention to how they apply or whether they matter. Take your Stiles-Crawford effect: how significant is it in the scotopic conditions under discussion here, and just how "false" then are these usual calculations?

 

[Jessie-66]

Image stabilised binoculars were mentioned in the thread, I don't know any mathematical models, formulas for that. All together could try some research, at least literary search, brain storming. In the Cloudy Nights forum, Prof. Ed Zarenski (user EdZ) has published studies with values for the resolution of classical binoculars with different types of support: handheld, elbow supported, tripod. Perhaps the formula of Köhler and Leinhos can at least be adapted for the special cases of low light and twilight? Or use one of the usual interpolations (least squares method, diverse polynomial interpolations). Besides Matlab, there are also free numerical mathematics programs, e.g. open source GNU Octave for GNU/Linux or FreeMat (Windows?).
Maybe IS binoculars are not much different than classic ones, it can just be a constant or a linear function added to the already known resolution gain?