Tuesday, December 4, 2012

Quartz fluorite len vs enlarger lens for reflected UV photography

Today about comparing a quartz fluorite lens with a conventional, but UV capable enlarger lens. I'm using a beautiful flower, Eucharis × grandiflora, also called Amazon Lily, for that as well as my "work horse" UV filter, the Baader-U filter and a Hamamatsu f3.5/50mm quartz fluorite lens as well as a 3.5/50mm 6e/4g enlarger lens,a Komuranon-S 3.5/50mm. Light source was an UV enhanced Xenon flash.

[click on image to see a larger one]
1) Quartz Fluorite lens:
visible light image:
 

"standard" UV image using Baader-U filter:
 

UV - VIS differential:
 

2) Enlarger lens:
visible light image:
 

"standard" UV image using Baader-U filter:
 

UV - VIS differential:
 

This flower does not have a very prominent UV pattern, nor does it reach very deep into UV, so this comparison here is limited to the range down to about 370nm, bare that in mind. The quartz fluorite lens is teh much sharper one and also has less fovus shift, but still the enlarger lens seems to be useful, at least as a beginners lens for reflected UV photography.

Here the transmission chart of that enlarger lens, as compared to my "standard" comparison lenses which reveals that it transmits UV quite similar to a Noflexar 35mm to about 335-340nm.
 

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