I did a test of 10 of my UV-capable 35mm F3.5 lenses today.
This is the list of lenses in the shootout:
1) Novoflex Noflexar 35mm F3.5 macro lens (I used this lens to do custom whitebalance with my reference lens cap on lens pointing at subject. All images shot using this whitebalance setting)
2) Kuribayashi Petri Orikkor 35mm F3.5 lens
3) Petri 35mm F3.5 lens
4) Petri CC 35mm F3.5 breechlock lens
5) Mayfair Crystar 35mm F3.5 lens
6) Prinzgalaxy 35mm F3.5 lens 7#### serial number
7) Photax 35mm F3.5 lens 7#### serial number
8) Soligor 35mm F3.5 lens 9##### serial number (not Kuribayashi clone)
9) 35mm F3.5 old enlarging lens (Aico)
10) 35mm F3.5 new enlarging lens (Aico-PSL)
Camera: Olympus E-PL5 (full-spectrum with Spectrosil 2000 in place of ICF)
Setup: Camera mounted on Kirk Low pod and placed on garden table, triggered with wired remote
Place: My back garden in Oxford, UK
Subject: Rudbeckia, Zinnia and other flowers
Light source: full direct sunlight. Shooting took quite a while as I had to halt shooting until there was unrestricted direct sunlight shining on the flowers.
Settings: ISO 800, Aperture mode, custom whitebalance set with Noflexar & Baader U. All lenses set to their respective F4 aperture.
Filters: Baader U for wide-spectrum UV and 330AF20 for narrow bandwidth (between 320 to 340nm)
This test is for comparing overall and deeper UV transmission between the lenses tested; it is not for testing sharpness or other lens characteristics. I have tried to reduce variables as much as possible. But it does not take into account the difference in aperture size between lenses – which does explain the results obtained from the best-transmitting lens.
I am assuming the direct sunlight is producing the same about of UV while testing all the lenses; the fact the retest yielded the same results should support this assumption.
One other hiccup i encountered was that the Petri breech lock lens could not reach focus at the original position where I shot the other lenses and hence it was tested last, with the camera moved towards the flowers – that could have affected its shutter speed. The enlarger lenses were tested last of all but adjusting framing to be similar to that of the other lenses.
Here is the setup I used for testing: