Today about a highly specialized UV lens, the ELCAN (Ernst Leitz CAnada) UV f5.6/52mm lens, a one-off prototype (I don't know of any other special UV lens Leitz/Leica has ever made). In lack of a flower with UV pattern, I'm using a African violet hybride flower for that test as well as my "work horse" UV filter, the Baader-U filter. Light source was a modified Xenon flash. All shots were done at f8.
[click on image to see a larger one]
Visual light image:
Reflected UV using Baader-U filter:
Simulated Bee Vision image:
Triptych Visual, reflected UV, Simulated Bee Vision (left to right):
This specialized UV lens works very well, there is hardly any focus shift visible, not even between UV and IR (!), contrast is high, there is no visible hotspot and the lens renders very sharp and crispy images. A welcome new member of my small collection of such specialized lenses.
P.S.: The images were not re-adjusted in focus between all shots, to show that there is no visible focus shift between VIS and 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