Saturday, August 17, 2019

The Bausch & Lomb f4.5 / 9" (229mm) lens for reflected UV

Quite a few years ago I got an older lens, which was made many years ago by famous lens maker Bausch & Lomb, Rochester NY. It is a golden color coated, heavy and well made f4.5 / 9" (229mm) lens which attracted me, since it was made to record images displayed by a P-16 phosphor screen. Nothing special actually, but since P-16 phosphor emits at about max. 380nm, that attracted me most for my UV work.


A while ago I tested it against the Coastal Optics Micro Apo 105mm and the Nikon UV Nikkor 105mm and it perfomed very well.

[click on image gets you a larger image]

Today now the spectrometric results in comparison to the Kuribayashi 3.5/35mm lens, one of the best performing "normal" lenses for UV:

It gets pretty clear that the B&L lens has a very high UV performance, at 365nm it transmits 74%, whereas the Kuribayashi has 80%, so very close to it. A very useful long focal length lens for reflected UV.

Stay tuned, more will follow on that fascinating subject...

More info on this very interesting field may be found on my site