Using an older Quartz Fluoride Condensor as a taking lens

A while ago, on my search for affordable lenses for reflected UV photography, I discovered in an older UV-VIS spectrometer system some seemingly useful Quartz Fluoride Lens system (QFC) of approximately f3.2 / 81mm. It had to be modified to convince it to work with a camera, and also a variable aperture had to be added, but I succeeded finally to get it to work on a mft camera system.

So today a comparision between my "work horse" UV-Nikkor f4.5/105mm (top) and this QFC f3.2/81mm (botttom):


Both images are a Quadriptych of VIS, reflected UV, sim. Butterfly and Bee vision (left to right, top to bottom)

Both lenses differ in focal length, 105mm for the UV-Nikkor vs 81mm for the Quartz Fluoride Condensor lens, and lens speed f4.5 vs f3.2 but other than that they are quite comparable: there is hardly any focus shift, just sharpness and contrast is higher with the rather expensive UV-Nikkor lens compared to the Quartz Fluoride Condensor lens, quite as expected. Other than that this old lens does very well, but it only covers mft sensor format, possibly APS-C (with another modification).

Another fascinating and beautifuly executed experiment. How is it that scientists can extrapolate what insects that we know can see in the ultraviolet range actually see?

Peter Dexter said:

Another fascinating and beautifuly executed experiment. How is it that scientists can extrapolate what insects that we know can see in the ultraviolet range actually see?

Click to expand...

Thanks Peter! Scientists have been working since many decades on that, so it is now quite know what teh spectral sensitivities of bees and beutterflies are; based on that I developed my filtering and color mapping techniques.

Interesting. I wasn't sure what a Quadriptych was so I had to Google it. Even so, I'm still not sure what I'm seeing. I think I need to do some more research.