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Message: <blockquote data-quote="Gijs van Ginkel" data-source="post: 3432283" data-attributes="member: 82596">Dennis, Post 28,I do not know what makes you conclude that there is a "huge"difference in blue transmission between the SF and the SV. The difference is 3,4% at 450 nm and there is only a very small difference  in transmission between 500-600nm. Both spectra are fairly flat over a broad spectral region: an excellent basis for a very good color reproduction for both binoculars. A binocular that really showes a transmission dip in the blue region is the Leica Ultravid HD-plus 8x42, in which HT glass was applied.With regard to low light sensitivity; rod vision at very low light intensity has its maximum sensitivity around 500 nm, but much more interesting for birders is the low light level where rods and cones are both excited: the mesopic light level. That requires an optimal transmission for both night and daylight vision so between 475 and 575 nm. I can only conclude from the spectra we have measured, that both Zeiss and Swarovski have taken this into account and that must be the reason that the spectra of both binoculars are almost flat in that spectral region.Actually, when Dr Jedamzik, optical glass specialist of Schott AG introduced the new HT glass one of his remarks was that this type of glasses used in binoculars can significantly improve their mesopic vision capabilities. Zeiss and Swarovski do not mention whether they have used that type of glass in the SF or SV, Leica did  for its HD-plus, but not with the excellent results Zeiss and Swarovski have realized with or without HT-glasses. But both did not realize high transmission values over 90% as they also did not pretend in the SV and SF flyers if I remember well.Gijs van Ginkel.</blockquote>

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