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ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

Light transmission comparison esp. Zeiss (1 Viewer)

S

SeldomPerched

Well-known member
Can anyone point me to a comparison chart not just for Zeiss (which is the brand I think of where light transmission is discussed, because of the AK prism advantage) but other makes? There are a few things I've been wondering which would be cleared up by looking at a single table:

Does the transmission figure have to differ between say 8x and 10x versions of the same binocular?

Is 95% transmission the highest achieved as in the recently discontinued Victory HT? And also I believe by the 7x42 T*FL and maybe other FLs?

A how many percent difference is needed to be discernible by the human eye (a good one)?

And can someone point me again to the writing by Holger Merlitz which explained comparative visibility between say white objects from different distances and larger objects at different distances and other such things?

Thank you.

Tom
 
Tom,

You can download Holger's paper by clicking the link at the bottom of the introductory section here.
https://www.birdforum.net/showthread.php?t=385328

What the work of Berek (in that paper) and Köhler and Leinhos indirectly shows is that the proportion of the available light reaching the retina is a relatively unimportant factor in target detection and apparent acuity until you get down to moonlight light levels. What we know now, but those guys didn't appreciate then, is the importance of blue and violet performance, particularly after sunset. Unfortunately Gijs data cuts out some of the blue and all of the violet parts of the spectrum, so is of rather limited value. The HT glass used in the Zeiss HT and Noctivid for example, principally improves binocular transmission in the 380nm to 450nm region.

David
 
Typo, post 3,
If you look at the daylight sensitivity curve of the eye, you will see, and you know, that the eye has a ver low sensitivity for light below 450 nm and above 720 nm, see also figures 21 and 26 of my review paper "Color vision, brightness , resolution and contrast in binocular images" also published on the WEB-site of House of Outdoor.
That is my only response to your post 3, I will not discuss that any further.
Gijs van Ginkel
 
I don't know where Gigs found those plots, but the first screenshot attached shows a plot of the current CIE 2006 luminosity function. The second screenshot is from Nature 26756 (2016) that shows that the spectrum of the ambient light is predominantly in the blue and violet deep into twilight.

David
 

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Last edited:
typo said:
Tom,

You can download Holger's paper by clicking the link at the bottom of the introductory section here.
https://www.birdforum.net/showthread.php?t=385328

What the work of Berek (in that paper) and Köhler and Leinhos indirectly shows is that the proportion of the available light reaching the retina is a relatively unimportant factor in target detection and apparent acuity until you get down to moonlight light levels. What we know now, but those guys didn't appreciate then, is the importance of blue and violet performance, particularly after sunset. Unfortunately Gijs data cuts out some of the blue and all of the violet parts of the spectrum, so is of rather limited value. The HT glass used in the Zeiss HT and Noctivid for example, principally improves binocular transmission in the 380nm to 450nm region.

David
Click to expand...

Thank you for the link to Holger's paper, David. The wavelength dispute is going to be too complicated for me though.

Tom
 
Gijs van Ginkel said:
Typo, post 3,
If you look at the daylight sensitivity curve of the eye, you will see, and you know, that the eye has a ver low sensitivity for light below 450 nm and above 720 nm, see also figures 21 and 26 of my review paper "Color vision, brightness , resolution and contrast in binocular images" also published on the WEB-site of House of Outdoor.
That is my only response to your post 3, I will not discuss that any further.
Gijs van Ginkel
Click to expand...

Hi Gijs, I will have a look at your link as posted by Troubadour; thank you for your testing.

Tom
 
Transmission

Troubador said:
Tom
Go to: https://www.houseofoutdoor.com/verrekijkers/verrekijkers-testen-en-vergelijken/

There are plenty of test graphs there to keep you happy until Easter at least.

Lee
Click to expand...

200116

Considering our physiological differences, accommodations, and the fact that a binocular manufactured Tuesday at 9:00 a.m. will differ slightly from the “same” binocular manufactured Thursday at 3:00 p.m., could someone point out to me why—other than being fodder for chat—this is really relevant? I’m not being flippant. If there is an answer that will hold up to the scrutiny of physics and biological imperfections, I would like to know of it. And the answer will not come from a manufacturer’s promotional chart.

Just a thought.

Bill

PS I only mention this nitnoid stuff because some people seem to build a life around it. They think it of paramount importance to rearrange deck chairs on Titanic. If you don’t like your binocular, you don’t need tests or graphics ... you need more money, at least until the next wave of Blarney washes over you.
 
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WJC said:
200116

Considering our physiological differences, accommodations, and the fact that a binocular manufactured Tuesday at 9:00 a.m. will differ slightly from the “same” binocular manufactured Thursday at 3:00 p.m., could someone point out to me why—other than being fodder for chat—this is really relevant? I’m not being flippant. If there is an answer that will hold up to the scrutiny of physics and biological imperfections, I would like to know of it. And the answer will not come from a manufacturer’s promotional chart.

Just a thought.

Bill

PS I only mention this nitnoid stuff because some people seem to build a life around it. They think it of paramount importance to rearrange deck chairs on Titanic. If you don’t like your binocular, you don’t need tests or graphics ... you need more money, at least until the next wave of Blarney washes over you.
Click to expand...

I know what you mean Bill but in Tom's case I am sure it is healthy curiosity.

Lee
 
WJC said:
200116

Considering our physiological differences, accommodations, and the fact that a binocular manufactured Tuesday at 9:00 a.m. will differ slightly from the “same” binocular manufactured Thursday at 3:00 p.m., could someone point out to me why—other than being fodder for chat—this is really relevant? I’m not being flippant. If there is an answer that will hold up to the scrutiny of physics and biological imperfections, I would like to know of it. And the answer will not come from a manufacturer’s promotional chart.

Just a thought.

Bill

PS I only mention this nitnoid stuff because some people seem to build a life around it. They think it of paramount importance to rearrange deck chairs on Titanic. If you don’t like your binocular, you don’t need tests or graphics ... you need more money, at least until the next wave of Blarney washes over you.
Click to expand...

Hi Bill,
I was only curious really - it won't make any difference to what I like to use in practice. Sometimes -- is this just me? -- I like to have a chat and if it's something I'm interested in so much the better but it's more about the journey than the arrival, to be honest! (Which sounds like being a timewaster but when using such amazing observational tools I am interested in some of the detail even if the science/physics soon overtakes me...)

Best wishes,

Tom
 
Troubador said:
I know what you mean Bill but in Tom's case I am sure it is healthy curiosity.

Lee
Click to expand...

Yes, I think that is spot on, Lee. I get a lot of enjoyment out of my glass, same as shooting film or digital with a camera, and knowing a bit about it seems a natural thing to follow on with.

Tom
 
Tom, Lee, I couldn't agree more with your last remarks.
I started using binoculars to be able to see birds closer (which is important enough a task). However, in the process of finding and chosing the right binoculars for me, I discovered binoculars themselves, and the pleasure and joy relative to their use but also to the understanding of the way they work and the little details around them.

I understand Bill's point; his advice is always wise and his comments mostly darts filled with experience that hit on target (I guess 99 % of the population would agree that most of what's written in this subforum could be described as as "futile hair-splitting exercise"), but then, this whole thing reminds me of the time I started (heavily) using a bicycle. In the beginning I just wanted to go from point A to point B, but then I was captivated by its mechanical simplicity, the fact that there were no electronics, but pure good ol' engineering, and after several years I discovered myself learning how to thread bicycle wheels. There is an inner (dare I say intimate) joy in the use of these lovely devices that make you want to know more details (although in doing so it is actually easy to fall in the spider web of publicity blurb). Let's rejoice in the details :)
 
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yarrellii said:
Tom, Lee, I couldn't agree more with your last remarks.
I started using binoculars to be able to see birds closer (which is important enough a task). However, in the process of finding and chosing the right binoculars for me, I discovered binoculars themselves, and the pleasure and joy relative to their use but also to the understanding of the way they work and the little details around them.

I understand Bill's point; his advice is always wise and his comments mostly darts filled with experience that hit on target (I guess 99 % of the population would agree that most of what's written in this subforum could be described as as "futile hair-splitting exercise"), but then, this whole thing reminds me of the time I started (heavily) using a bicycle. In the beginning I just wanted to go from point A to point B, but then I was captivated by its mechanical simplicity, the fact that there were no electronics, but pure good ol' engineering, and after several years I discovered myself learning how to thread bicycle wheels. There is an inner (dare I say intimate) joy in the use of these lovely devices that make you want to know more details (although in doing so it is actually easy to fall in the spider web of publicity blurb). Let's rejoice in the details :)
Click to expand...

Yarrellii, this is sort of the way I feel. I suppose the danger, though there's not really anything wrong with it, is when that joy takes over too much from the intended purpose of having binoculars in the first place.

In my case this is a period when there isn't too much opportunity to go out using them, so a spell at the screen is displacement activity that takes up less time. This usually lasts a few days or maybe a week or so, then I return to other interests or nature watching instead of semi-theoretical systems checking.

I take on board Bill's points too, and it's disappointing that sample variation seems such a fact of life with precision instruments. Since we are on the Zeiss forum this might be a good time to say that within the limits of my own eyesight my own Zeiss kit seems very very good in almost all lighting conditions. The old Dialyt 7x42 continues to give breathtakingly clear views with what to me is a very beautiful colour rendition. Just no use for close ups.

Hoping to get out tomorrow or Sunday; recently I missed the chance to see a large murmuration at closer range as I had no binos with me - mind you the overall effect was better captured with the naked eye anyway.

Tom
 
yarrellii said:
Tom, Lee, I couldn't agree more with your last remarks.
I started using binoculars to be able to see birds closer (which is important enough a task). However, in the process of finding and chosing the right binoculars for me, I discovered binoculars themselves, and the pleasure and joy relative to their use but also to the understanding of the way they work and the little details around them.

I understand Bill's point; his advice is always wise and his comments mostly darts filled with experience that hit on target (I guess 99 % of the population would agree that most of what's written in this subforum could be described as as "futile hair-splitting exercise"), but then, this whole thing reminds me of the time I started (heavily) using a bicycle. In the beginning I just wanted to go from point A to point B, but then I was captivated by its mechanical simplicity, the fact that there were no electronics, but pure good ol' engineering, and after several years I discovered myself learning how to thread bicycle wheels. There is an inner (dare I say intimate) joy in the use of these lovely devices that make you want to know more details (although in doing so it is actually easy to fall in the spider web of publicity blurb). Let's rejoice in the details :)
Click to expand...

You make a good point, and then bicycles, I suppose there are many forums on that subject also.
It seems we all need something to talk about. The subject of light transmission is a bit subjective. The machine measured results are a bit
iffy as they do vary among testers.
What you see among those offering their own personal views on what they see also varies. ;)

Jerry
 
yarrellii said:
Tom, Lee, I couldn't agree more with your last remarks.
I started using binoculars to be able to see birds closer (which is important enough a task). However, in the process of finding and chosing the right binoculars for me, I discovered binoculars themselves, and the pleasure and joy relative to their use but also to the understanding of the way they work and the little details around them.

I understand Bill's point; his advice is always wise and his comments mostly darts filled with experience that hit on target (I guess 99 % of the population would agree that most of what's written in this subforum could be described as as "futile hair-splitting exercise"), but then, this whole thing reminds me of the time I started (heavily) using a bicycle. In the beginning I just wanted to go from point A to point B, but then I was captivated by its mechanical simplicity, the fact that there were no electronics, but pure good ol' engineering, and after several years I discovered myself learning how to thread bicycle wheels. There is an inner (dare I say intimate) joy in the use of these lovely devices that make you want to know more details (although in doing so it is actually easy to fall in the spider web of publicity blurb). Let's rejoice in the details :)
Click to expand...


Hello,

I can relate fully to your sentiments , there is great satisfaction in using well made and engineered artifacts of whatever nature , binoculars , bicycles , guns , old tools etc..

But some people just do not understand------------.

o:D :-O o:D

Cheers.
 

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