Lilcrazy directed me to allbino website where they do testing of various binocs including stats on light transmission. Interestingly, most of the roofs are around 91+- percent range, though some are higher like the Zeiss. Some have told me about the nikon SE brightness but they are porros. The allbino site said tranmission was very high at 96%.
My question is this, when I see Zen Ray talk about 99.5% light transmission and others referring to dialetic coatings at 99%, is that reliable and comparable? In other words, if I had a Vortex Viper 10x42 w/ 92% tranmission and compared to a 10x43 ED2 Zen where they claim 99.5%, should I expect the Zens to be noticeably brighter given the huge difference in tranmission?
Have manufacturers really reached perfection and all new highs w/ dialetic coatings at 99+ percent? The allbino doesn't do any testing on the new zens or nikon atb's w/ dialectics.
Afaik, the 99+% transmission is for one single glass/air interface.
The overall transmission is much less because there are many such interfaces in the optics of a binocular.
The transmission % is also an inadequate measure, as it typically reflects only the frequency with the highest performance. There is a lot of leeway for the manufacturers to favor one end of the spectrum or the other, but that would take more expert insight than I have.
As an aside, the old Zeiss Jena 7x40 porro only had about 70% transmission, but gave a delightfully easy view.
So higher transmission is not essential to getting a good experience.
[QUOTE=etudiant;2059033]Afaik, the 99+% transmission is for one single glass/air interface.
The overall transmission is much less because there are many such interfaces in the optics of a binocular.
The transmission % is also an inadequate measure, as it typically reflects only the frequency with the highest performance. There is a lot of leeway for the manufacturers to favor one end of the spectrum or the other, but that would take more expert insight than I have.
As an aside, the old Zeiss Jena 7x40 porro only had about 70% transmission, but gave a delightfully easy view.
So higher transmission is not essential to getting a good experience.[/QUOTE]
Just one correction. The transmission at each surface, or the system as a whole, is computed relative to a reference beam of spectral light. Total transmission is basically an average over the spectral components. Peak transmission frequencies vary from one instrument to another, primarily due to the coating formulation. The shape of the transmission spectrum influences the resultant color balance that is perceived.
Ed