I'm having a braincramp (not uncommon) as to the uv filtering properties of glass more specifically G-15 glass lenses. As I recall it's significant (98%?) otherwise Photochromic lenses would darken in an enclosed sunlit room.
Does someone know of a chart I can print out for all lens uv filtering properties?
You might want to check with X-cel. If anyone would have it, they would.
These might help:
Lens Material Chart
Spectral Transmittance Charts
Darryl J. Meister, ABOM
Thanks Darryl it does help.
Will the tint effect these rates?
Optiboarders RULE:cheers:
Percentage of UV Absorbed up to 380nm:
(by Lens Type)CR-39 Plastic
58%
CR-39 Plastic
(w/UV Dye)
100%Polycarbonate
100%Hi-Index Plastic
100%Mid-Index Plastic
100%Transitions - All Materials
100%Polarized CR-39 Plastic
100%Polarized Crown Glass
(All Colors)
100%White Crown Glass
16%UV Treated Glass
100%PhotoBrown Extra Glass
96%PhotoGrey Extra Glass
96%PhotoGrey Thin & Dark Glass
96%Grey #3 Crown Glass
95%Green #3 Crown Glass
99%Tan C Glass
99%G-15 Glass
97%Pink #2 Crown Glass
92%Pink #1 Crown Glass
90%Canary Yellow Glass
100%Rose Didymium Glass
89%Corning Clear 1.60 Glass
77%Hi-Index 1.60 Glass
78%Hi-Index 1.70 Glass
82%Hi-Index 1.80 Glass
86%
Information provided by X-Cel Tech Data
Keep in mind that the transmittance at 380 nm isn't really the "UV transmittance" of the lens. UV transmittance is defined as the average transmittance over a defined range of wavelengths. Common CR-39 from many lens suppliers blocks 100% UVB (290-315 nm) and 90% or more of UVA (315-380 nm).from X-Cell, but only up to 380nm
Yes, in both plastic and glass, darker tints will significantly reduce UV transmittance, with or without the additional UV treatment.Will the tint effect these rates?
Darryl J. Meister, ABOM
Can't find anything for the B&L G15.
Green 3 glass- Abbe 52.3, 2.3CT
% UV B Transmittance 0.0
% UV A Transmittance 0.3
% Blue Transmittance 22.3
UV cutoff at 360nm
Gray 3 Glass- Abbe 54, 2.0CT
% UV B Transmittance 0.0
% UV A Transmittance 3.7
% Blue Transmittance 13.0
UV cutoff at 340nm.
Tan 3 Glass Abbe 51.9 2.0CT
% UV B Transmittance 0.0
% UV A Transmittance 0.2
% Blue Transmittance 7.6
UV cutoff at 360nm.
From OLA's Spectral Transmission of Lens Materials- Daniel Torgerson 1998
Science is a way of trying not to fool yourself. - Richard P. Feynman
Experience is the hardest teacher. She gives the test before the lesson.
There are currently 1 users browsing this thread. (0 members and 1 guests)
Posting Permissions
Reply With Quote
Bookmarks