Showing posts with label P-16. Show all posts
Showing posts with label P-16. Show all posts

Wednesday, September 18, 2019

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

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) Phosphor 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]

The spectrometric results in comparison to the Kuribayashi 3.5/35mm lens, one of the best performing "normal" lenses for UV reveals that is very useful for reflected UV:



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 with quite high UV transmission and reaching rather deep into the UV range for a non quartz fluorite lens.

So and here a few shots I took the other day with it, first the roof of the neighbour house about 20 meters away:


Then a Rudbeckia hirta flower on my balcony from about 4 meters away:

It is indeed a rather sharp lens for reflected UV, which allows a nice working distance, if so needed. A good addition to the rare tools for reflected photography!

I have written HERE more about it.

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

More info on this very interesting field may be found on my site http://www.pbase.com/kds315/uv_photos

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 http://www.pbase.com/kds315/uv_photos