4 replies to this topic

[Cadmium]

The Kuribayashi Petri Orikkor 35mm f/3.5 with M42 mount transmits UV down to 325nm,
which is deeper UV transmission than any Nikkor lens, short of the UV-Nikkor costing much more, and slightly deeper UV transmission than a Noflexar 35mm lens.
The M42 mount can be converted easily. My inexpensive M42-to-Nikon converter with built in corrective infinity focus lens (which you will not need with many cameras) has no effect on the UV transmission or depth.
This lens has miniscule to no focal shift, and comes in other versions, such as the W.Acall Kyoei 35mm f/3.5 (and other Kyoei clones).
Some examples of Kyoei/Kuri clones:
http://www.savazzi.n...phy/35mmuv.html
http://myphotojourne...mm-f3-5-lenses/

If you shoot UV, and don't want to spend $1,000.00's on a UV lens, then try to find one of these.
This is old news, but I am posting it here because things can disappear on other sites sometimes.
1) Kuribayashi lens.
2) Sparticle bandpass filter holder transmission test of Kuri 35mm with Baader U filter on lens.
3) Barn shot with Kuri 35mm and Baader U filter (320-400nm).

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[Andrea B.]

Thank you Steve for this good reference post. It is always nice to have a photo of these lenses. I will link this in the Lens Sticky.

I would add that for the Kuri clones, we do not have transmission info about all of them. Some Kuri clones may not transmit as deeply as others. But then, as Bjørn has pointed out in another thread recently, most UV shooting is done in the 350-400 nm range.

I have the W.Acall Kyoei 35mm f/3.5 and find it to be a really nice lens in general terms as well as being UV-capable.

[Cadmium]

The UV band width (or depth) of the lens transmission curve is important because it has a lot to do with attenuation of what the filter is capable of transmitting.
The strongest amplitude of a UV filter is at it's peak wavelength, so it is best for a lens to start transmitting as deeply below the filter peak in order to incorporate and utilize that peak amplitude within the lens transmission profile, which also maximizes transmission above the peak as well as below.
Attenuation of the filter transmission by the lens will move the peak wavelength to a higher wavelength (changing false colors and white balance), reduce amplitude, and increase exposure time.
All other settings and equipment being the same, exposure time between UV lenses is another indication of capability.
Here is a combined transmission graph of several lenses using the same filter stack. I don't expect this graph to be exact, but it is a rough illustration of this idea.

Edited by Cadmium, 30 November 2015 - 07:23.

[Andrea B.]

Steve, a question, please & thank you. What is the y-axis measuring? Percentage transmission? If so, how were the lenses measured?

Nice to see the Kuri holding up well there!!

[Cadmium]

That is the transmission %, just like with filters. I must have accidentally cut off the side label when made the graph.
Schott uses 0 to 1 instead of 0 to 100 %.
I must have missed your question back then.