What if...... (1 Viewer)

[Gijs van Ginkel]

Hello Jan,
You caught me in the middle of the calculations and writing the report, so the values have to be slightly corrected: for the Retrovid 7x35B we found:
500 nm= 90%
550 nm=92%
Gijs van Ginkel

 

[henry link]

Hello Jan,
I assume that you are asking for the Retrovid 7x35B transmission data.
We found the following:
500 nm=90,6%
550 nm = 92,6%
Hope that helps to concur all curiosity viruses.
Gijs van Ginkel

Thanks Gijs!

Correct me if I'm wrong, but I believe this is the highest transmission at these wavelengths for any Leica binocular you've tested: certainly very impressive for any binocular with 16 glass to air surfaces and an S-P prism. Naturally I can't help but wonder how much better a faithful reissue of the old Trinovid design would have been with only 10 surfaces and an Uppendahl prism, maybe 95% at 550 nm?

Do you think Leica has improved its coatings since 2017 when your measurement of the Noctivid 8x42 was 88% at 500 nm and 90.1% at 550 nm?

Henry

 

[Renze de Vries]

Hello Jan,
You caught me in the middle of the calculations and writing the report, so the values have to be slightly corrected: for the Retrovid 7x35B we found:
500 nm= 90%
550 nm=92%
Gijs van Ginkel

These figures are so impressive that I can't escape from the notion that they cry out for interpretation. And I mean thorough interpretation. I went to Gijs' tests on other binoculars, to avoid deviations caused by the test equipment and found quite remarkable things. For instance: except for the Zeiss HT no high end 42/44 mm binoculars in 8 or 10 mag. reach these figures. No Swaro EL, no Zeiss SF, no Leica Noctivid. The opposite however is the case with compact binoculars of 8x25 format, where models of Zeiss, Swarovski and even Bynolyt soar to 93, 94 and 95 %.
Gijs, what's happening here? How to interpret your transmission figures?

Renze

 

[Binastro]

With small binoculars there is less glass and some small binoculars have remarkably few elements.

I was just watching a video about Arri Signature lenses and there was a comment that some of the glass used was more expensive than gold.
But the lenses cost $25,000 each.

Possibly made by Zeiss or Fujinon, although I am not sure.

B.

 

[henry link]

These figures are so impressive that I can't escape from the notion that they cry out for interpretation.

Renze

Hi Renze,

I agree the 7x35 Retrovid measurements are impressive, but I don't think they're so high that they require an explanation. Looking back at Gijs' tests I see that his 2009 measurement of the Zeiss 8x32 FL was 93% at 550 nm, in good agreement with Zeiss' own measurement of 92.3% supplied to me in 2004. For purposes of light transmission the 8x32 FL design closely resembles the Retrovids, with the same number of glass surfaces and the same prism type.

Henry

 

[Ontario]

New vs Old Data

Hello Jan,
I assume that you are asking for the Retrovid 7x35B transmission data.
We found the following:
500 nm=90,6%
550 nm = 92,6%
Hope that helps to concur all curiosity viruses.
Gijs van Ginkel

New vs Old

 

[tenex]

Tenex, I am curious. What compromises in performance are you referring to that 42mm binoculars have suffered? Glare? FOV?

Yes, primarily FOV (consistently even less than the same 32s or 50s). Sometimes also glare esp. if the objectives aren't well recessed, or distortions from using too short a focal length, limited close focus (not as common a problem today), even inadequate eyecup height. (Perhaps weight can also limit the amount of glass in a design?)

 

[Gijs van Ginkel]

Renze, post 383,
That is the way it is, we checked the data several times and have to accept the figures.
The 20 mm Leitz Ultravids also have high light transmissions as we again confirmed. The whole report will come soon, so everybody can compare (for BF convenience I wrote it in English this time).
Gijs van Ginkel

 

[jan van daalen]

So the first findings of the Retrovid are:
Solid and, as far as we can establish, genuine Leica built binocular with a more than acceptable FOV and with a light transmission that is top of its class.
Retro on the outside and state of the art on the inside.
Mmmm, not bad.
Wel done Leica (but you're out and stay outB ).

Jan

 

[Thomas_M]

Hello Jan,
You caught me in the middle of the calculations and writing the report, so the values have to be slightly corrected: for the Retrovid 7x35B we found:
500 nm= 90%
550 nm=92%
Gijs van Ginkel

Gijs,

thanks a lot also from my side for the interesting information,

Thomas

 

[[email protected]]

New vs Old

Even without UP Prisms the new Retrovid 7x35 really outperformed the old Trinovid 7x35.

 

[[email protected]]

Thanks Gijs!

Correct me if I'm wrong, but I believe this is the highest transmission at these wavelengths for any Leica binocular you've tested: certainly very impressive for any binocular with 16 glass to air surfaces and an S-P prism. Naturally I can't help but wonder how much better a faithful reissue of the old Trinovid design would have been with only 10 surfaces and an Uppendahl prism, maybe 95% at 550 nm?

Do you think Leica has improved its coatings since 2017 when your measurement of the Noctivid 8x42 was 88% at 500 nm and 90.1% at 550 nm?

Henry

"Naturally I can't help but wonder how much better a faithful reissue of the old Trinovid design would have been with only 10 surfaces and an Uppendahl prism, maybe 95% at 550 nm?"

Henry. I don't think it would have ever hit 95% transmission. That is getting up there in porro-prism Habicht transmission territory. I think you would have to have HT glass in it as well like the Zeiss HT to get that high.

 

[henry link]

"Naturally I can't help but wonder how much better a faithful reissue of the old Trinovid design would have been with only 10 surfaces and an Uppendahl prism, maybe 95% at 550 nm?"

Henry. I don't think it would have ever hit 95% transmission. That is getting up there in porro-prism Habicht transmission territory. I think you would have to have HT glass in it as well to get that high.

The Habicht's don't have HT glass. Their transmission is so high because their design is very simple and they use excellent modern coatings. The original Trinovids benefited from an almost equally simple design, so with equally good modern coatings they shouldn't be far behind the Habichts. The original 7x35 had two fewer glass surfaces than the 8x30/10x40 Habichts and a cemented Uppendahl with modern mirror coatings should be pretty close to an uncemented Porro I. Gijs measured 95.9% for the 8x30 Habicht at 550 nm. 95% seems about right for an updated 7x35 Trinovid with the best modern coatings.

 

[[email protected]]

So the original Trinovid with UP prism's was really almost as simple of an optical design as the Habicht porro with two fewer glass surfaces. I wonder what the transmission would be on a Habicht or the original Trinovid would be with HT glass? 97 to 98% maybe. By the way you are not talking about Habitat for Humanity are you?

 

[chill6x6]

Hello Jan,
I assume that you are asking for the Retrovid 7x35B transmission data.
We found the following:
500 nm=90,6%
550 nm = 92,6%
Hope that helps to concur all curiosity viruses.
Gijs van Ginkel

Impressive results!

Thanks Gijs and Jan for supplying the binocular! Both of you have added a lot to this forum!

 

[John A Roberts]

Highest Leica Transmission?

The highest transmission Gijs has recorded for Leica roof prisms is from the 8x20 Ultravid
The details are from a 2005 (!) test ‘Compact kijkers’ at: https://www.houseofoutdoor.com/verrekijkers/verrekijkers-testen-en-vergelijken

The test states 94% at 555 nm, and from the attached graph it would be around 92% at 500 nm


From previous Leica catalogues, we know that both the 8x20 and 10x25 UV’s have a relatively simple construction of 6 lenses per side

Based on published images, the detail is:
- Objective of 3 elements in 2 groups: 2 + 1 focusing
- Eyepiece of 3 elements in 2 groups: 2 + 1
and so only 8 air-to-glass lens surfaces!

See both a cutaway image of a 10x25 UV, along with a cross-section one of an 8x20 Monovid (which makes the eyepiece construction much clearer)


I’ve long thought the 8x20 UV's performance provides a significant insight into Leica’s use of multi-coatings
It’s not that Leica can’t make binoculars with as high transmission as Swarovski or Zeiss - but in balancing the factors that make up an image - they usually take a somewhat different approach
e.g. see my previous comments in the last part of this post: https://www.birdforum.net/showthread.php?t=370530


John

 

[Renze de Vries]

Renze, post 383,
That is the way it is, we checked the data several times and have to accept the figures.
The 20 mm Leitz Ultravids also have high light transmissions as we again confirmed. The whole report will come soon, so everybody can compare (for BF convenience I wrote it in English this time).
Gijs van Ginkel

Gijs,

Rest assured that I very much appreciate your efferts in providing the data. Also, I don't have any doubts that the figures you've come up with are correct.
My question however is their meaning: how to interpret these figures.

I simply compared transmission data from several of your tests and I was stunned. To the point that I wondered if I could draw any conclusions from transmission figures at all. What do they tell me? What don't they tell me? Should I be impressed? Or would it be better to consider other aspects as well before drawing enthousiastic conclusions? And if so, what would these aspects be?
In the meantime (Henri, John, Binastro) I've learned that I should not compare light transmission figures from binoculars of dissimilar optical construction. OK, fine. But it seems from John's contribution that there's more. For instance he led me to Tobias Mennle's findings (or suggestions) on this interpretation path that made me aware of how simple my thinking was. If I understand the issue correctly it's not simple at all. The question is: how to go about these things. Quote Tobias: 'I now think that transmission curves are pretty useless to determine the brightness of a binocular´s image, although they are very interesting with regards to color reproduction'.

(Find Tobias thoughts here; http://www.greatestbinoculars.com/allpages/articles/itsthebaffling.html)

Renze

 

[jan van daalen]

The final findings of the report from Gijs are on our website.

https://www.houseofoutdoor.com/wp-content/uploads/2020/02/Leica-kijker-test-dd-25-febr-2020.pdf

Happy readings

Jan

 

[Gijs van Ginkel]

Renze, post 397,
I do not agree with Tobias Mennle at all. To understand brightness three parameters are of importance: exit pupil, transmission and color balance. The latter can be judged by eye, but you can also read from the transmission spectrum.
Since this comes up all the time on this forum I made a literature review entitled "Color vision, brightness, resolution and contrast in binocular images". It has been referred to on this forum and you can find it on the WEB-site of House of Outdoor.
Gijs van Ginkel

 

[Gijs van Ginkel]

Jan, post 398,
That is fast, Ida is a miracle woman
Gijs