Topic of UV transmission of lenses has been discussed previously on this topic:
https://www.largeformatphotography.i...ustar-37/page4
Reply# 37, UV transmission chart of various lenses.
Reply# 38, UV transmission graphs of Schneider lenses. Schneider graph for the 360mm Tele Xenar is for their last multicoated version according to Robert Kipling apps engineer at Schneider USA in the 90's. Note the APO artar which is a dialyte formula has about 80% transmission at 400nm. Rapid attenuation past 420nm of the APO Symmar (modern Plasmat) was specifically designed in for good color rendition using color films from that era. Color films were affected by UV light, to address this problem, view camera lens providers re-designed their offerings to attenuate uv to aid in color reproduction.
Lens coatings alone are not the primary factor to lens UV transmission, optical glass types figures into this. Schneider Xenar (circa 1967), Tele Xenar, D-Claron and Dagor type g-Claron appears to have the most UV transmission to 365nm.
Zeiss made a 105mm UV Sonnar for Hasselblad long ago with a transmission range of 215 to 700nm (quartz and fluorite elements used).
https://www.zeiss.com/content/dam/co...r-43105-en.pdf
This was a curiosity published some years ago on wet plate portraits and strobe power needed using modern light modifiers.
https://petapixel.com/2015/12/11/sho...udio-lighting/
12,000 watt seconds of strobe power seems lots today, back in the days of sheet film color transparency commercial AD images, 12,000 watt seconds of strobe power was very common. Bit surprised that strobe flash tubes with UV output specific to wet plate sensitivity needs.
Bernice
Bookmarks