Due to my interest in alternative light photography, I keep my eye out for lenses that would be suitable for reflected ultraviolet photography. When I had a chance to get this 78mm F3.8 quartz lens, apparently made by Universe Optics, I went for it. A week later I had it, along with some other equipment which while interesting, was not my focus.
The lens is used with RUVIS (reflected ultraviolet imaging system) kits typically used for crime scene investigation or for seeking the ultraviolet coronas created by electrical discharge. Using a strong filter, the lens passes all light except ultraviolet wavelengths around 254nm. What little light makes it through the filter and lens strikes an image amplifier composed of a microchannel plate and a phosphor screen. The MCP, when struck by a photon, releases a cascade of electrons which strike the phosphor screen, causing a momentary release of light.
My copy was missing the battery cover, but a little jury-rigging let me test it, and it really is quite interesting seeing any form of reflected-UV isolated and live. The sparkling green image was quite grainy, but still clear, and had a really neat vintage cinematic feel to it.
As near as I can tell, the kit I got is from 1988, made/sold by Horiba, and is branded SceneScope. Given its age, I haven’t been able to find much information about it overall, though the lens apparently used then is still for sale on several sites even today.
Quartz optics are able to pass light down to at least the 254nm required for RUVIS systems, and likely as far down as 200nm before attenuated significantly. On the long end, quartz optics are supposed to stop at 2000nm approximately. While that is good news for reflected-UV photography, despite the fact that this lens easily covers APS-C format and even can do 35mm, it is not quite an ideal lens for reflected-UV work due to its uncorrected nature.
Wide open it shows significant chromatic aberration in the visible spectrum (with IR-cut filter only) and focus shift between the UV and visible spectrum. Stopped down to F/5.6 or smaller, it does produce fairly usable images in reflected-UV.
Here are some sample images, mostly taken at F/5.6 if I recall correctly.
All ISO 1600, except for the watermelon shot which was ISO 400. The long exposure in it and some of the others imparted motion blur.