Light transmission: Trinovid 8x20 green BCA (1 Viewer)

[SeldomPerched]

Can anyone help, as internet searching has at best come up with ambiguities? The first and for nearly 25 years only binoculars I had were a compact pair of green armoured Trinovid 8x20 BCA in a little black leather etui or case. I thought they were amazing - that is till I got my first full-size 42s, a close out UV HD pre-plus 8x42. Then they just seemed fiddly but I will never part with them. (The 8x42 is long gone.) Gary retightened the hinges and recollimated the glass and they are not so bad now after all, but still a bit fiddly comfort-wise on the eye, however you hold them. First world problems...

I'm just looking to find the light transmission percentage. Serial no. from memory -- I know; how sad -- is 1205419 and they were bought new in 1993. I found a chart by Gijs but couldn't be sure it referred to my model. Anybody know?

Tom

 

[Gijs van Ginkel]

SeldomPerched, post 1,
I have measured the spectrum of an 8x20 BC from 1998 and found 85-86% light transmission, the data can be found on the WEB-site of House of Outdoor in the most recent report of the new Leica/Leitz Retrovids. (the test is in English).
Gijs van Ginkel

 

[John A Roberts]

Hi again Tom,

Gijs' tests can be found at: https://www.houseofoutdoor.com/verrekijkers/verrekijkers-testen-en-vergelijken/

He tested the 8x20 Trinovid on 2 occasions:
A) In 2020 ‘Test Leica verrekijkers’ - both 1978 and 1998 units, along with a 2004 Ultravid

B) In 2005 ‘Compact kijkers 2005’ - presumedly a then current production unit (?)

I’ve attached the relevant graph from each. And as can be seen from the first, the transmission increased dramatically over time!
Your 1993 era unit should perform somewhere between the two in the first graph, and most likely very close to the 1998 unit

The use of multi-coating on binoculars dates from the late 1970's. And from then on, both:
- the transmission level of the coatings improved, and
- more significantly in the early years, the number of surfaces that were multi-coated increased
(from perhaps only one, to some and then to all; in advertising, from ‘multi-coated' to ‘fully multi-coated’)

The 1978 unit in the first graph is likely only single coated, or alternatively mainly single coated along with one or two multi-coated surfaces


For context, I’ve also attached another graph from the 2005 test, showing the Ultravid’s performance compared to contemporary Swarovski and Zeiss Victory 8x20’s


John

 

[SeldomPerched]

SeldomPerched, post 1,
I have measured the spectrum of an 8x20 BC from 1998 and found 85-86% light transmission, the data can be found on the WEB-site of House of Outdoor in the most recent report of the new Leica/Leitz Retrovids. (the test is in English).
Gijs van Ginkel

Many thanks, Gijs. Your comparative tests are a mine of useful information.

All the best,

Tom

 

[SeldomPerched]

Hi again Tom,

Gijs' tests can be found at: https://www.houseofoutdoor.com/verrekijkers/verrekijkers-testen-en-vergelijken/

He tested the 8x20 Trinovid on 2 occasions:
A) In 2020 ‘Test Leica verrekijkers’ - both 1978 and 1998 units, along with a 2004 Ultravid

B) In 2005 ‘Compact kijkers 2005’ - presumedly a then current production unit (?)

I’ve attached the relevant graph from each. And as can be seen from the first, the transmission increased dramatically over time!
Your 1993 era unit should perform somewhere between the two in the first graph, and most likely very close to the 1998 unit

The use of multi-coating on binoculars dates from the late 1970's. And from then on, both:
- the transmission level of the coatings improved, and
- more significantly in the early years, the number of surfaces that were multi-coated increased
(from perhaps only one, to some and then to all; in advertising, from ‘multi-coated' to ‘fully multi-coated’)

The 1978 unit in the first graph is likely only single coated, or alternatively mainly single coated along with one or two multi-coated surfaces


For context, I’ve also attached another graph from the 2005 test, showing the Ultravid’s performance compared to contemporary Swarovski and Zeiss Victory 8x20’s


John

Thank you once again, John. Liking those charts very much that you supplied from Gijs.

**Your info about the history of coating was helpful too. I am not so well up on the development of binoculars but as you can probably tell from the next paragraph I have some hands on experience with camera equipment and have appreciated Leica's M system for low light and unobtrusive photography with 35 mm film. I know from that experience that quite often in a long production run coatings are updated 'silently', so for instance I'd imagine that with a lens like the Summilux 1.4/35mm produced from about 1961 through to about 1995 that while the optics remained unchanged the coatings would have been improved and extended through the different glass surfaces in the lens. Possibly also balsam formulae would have changed. Diverging somewhat I am interested to see that the Leitz Midland factory in Canada that took over or initiated production of many excellent lenses under Dr Walter Mandler, a German who moved there to take charge and then decided to make Canada his family home, is now I believe a base for Raytheon and it leads me to wonder if Leitz and Raytheon had shared technology. And thinking of German and Canadian production it seems that some Leica collectors prefer German made items while in fact there is no difference in quality and manufacturing between Canadian and German units. Personally I prefer Canadian for no particular reason, if I have a choice; possibly because the designs I like best in use mostly originated in Canada and only moved production to Germany if they continued to be made after about 1990. I see similar discussions on this forum regarding Portugal and Germany. Anyway...**

As mentioned, compared with a full size 42 the Trinovid 8x20 BCAs are fiddly to use but still occupy a useful and quite treasured place being dinky and a real jewel of manufacture; also to me they have some sentimental value with memories of departed family members and past times. I particularly like the style of the design as it was at that time, with metal ribbing on the shoulders/bridge and also they were supplied in an olive green tone that I find pleasing. I think Leica at that time may have used the same colour for some of their medium and full sizes too: I have a tiny booklet outlining the Leica product range including their latest of the time: Leica R6.2 SLR and lens system, Leica M6 and lens system including the amazing 75/1.4 Summilux-M, the Focomat V35 enlarger (wish I had never sold it), and the range of Pradovit enlargers with Colorplan lenses. In it are also the various Trinovid BA/BN binoculars; the picture shows 8 and 10x42 in black with ribbed shoulders and the 7x42 in olive green. But I am becoming nostalgic!

I will just add that at the time (early 1990s) my experience with Leica was stunning while things worked but I began to have some bad luck with service reliability: a new M6 jammed after one roll of film and had to be replaced under guarantee, and a Summicron 2/35mm came unscrewed in use away from home - in Italy while shooting the streets at night. Things have been much better since, however.

Thanks for listening!

Tom

 

[Gijs van Ginkel]

SeldomPerched, post 4,
It is my pleasure, good to read that my work is useful.
Stay healthy,
Gijs van Ginkel