Steinheil Cassarit 105mm vs UV-Nikkor 105mm for reflected UV photography

Today a comparison between the well known UV-Nikkor 105mm lens and the lesser known Steinheil Cassarit f4.5/105mm enlarger lens. I'm using a patterned Phalaenopsis flower for that comparison and my work horse UV filter, the Baader-U filter. Light source was an UV enhanced Xenon flash as well as a Nichia 365nm UV LED. All shots done at f8.

[click on image to see a larger one; UV-Nikkor is on the left, Steinheil Cassarir is on the right]

UV-Nikkor vs Steinheil 105mm: VIS image using UV/IR Cut filter and Xenon flash:
 

UV-Nikkor vs Steinheil 105mm: UV image using Baader-U filter (approx. 320-395nm) and Xenon flash:
 

UV-Nikkor vs Steinheil 105mm: UV image using Baader-U filter (approx. 320-395nm) and UV LED:
 


That Steinheil lens transmits down to about 330nm and at 365nm has about 65% transmission. It needs refocussing when used for UV and the focus difference VIS-UV is just 1.2%, which the corrected UV-Nikkor lens does not need.

This comparison shows, that the UV-Nikkor 105mm is very hard to beat, but this Steinheil lens does very well, especially when used with an UV LED, considering it being a simple triplet lens. Finding a longer focal length UV-capable lens is a hard thing to do, so that Steinheil seems to be rather useful!

I have written about other Steinheil lenses HERE.

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

[UV] STEINHEIL lenses for UV

As I was testing (again) lenses for UV photography, so I ran a few more spectrometric tests now on STEINHEIL lenses, which might be of interest. These are all M42 thread mount taking lenses in silver aluminum barrel.

[click on image to see a larger one]

UV transmission graph:


In terms of UV transmission, all are quite good (except the Culminar) but all exhibit focus shift.

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