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UltravioletPhotography

Links to Informal Lens Transmission Tests Using Pinhole, Sparticle, WB & More


Andrea B.

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update :: 23 July 2019 :: clarified comment. added new link.

 

There are some ingenious informal UV lens transmission tests on UVP. Here are some links ordered by posting date.

 

The titles are a reference to the methodology and are *not* the original post title.

 

This is not a complete list of all informal lens tests made by UVP members. It is only meant to point to the basic types of informal lens testing. I'm always happy to add links that you think should go here.

 

 

 

Cadmium: Sparticle Board

There are many examples on UVP. Here are just two.

01 Jan 2016

http://www.ultraviol...dpost__p__10628

 

See also

Cadmium: Sparticle vs. Diffraction Grating

01 May 2016

http://www.ultraviol...dpost__p__12424

 

Enrico Savazzi: Filter strip for testing UV lenses

 

OlDoinyo: Pinhole and Relative Color

11 Jan 2016

http://www.ultraviol...dpost__p__10955

 

 

Timber: Uniform White Balance and Relative Color

16 Sep 2016

http://www.ultraviol...ndpost__p__4452

 

 

Hornblende: Pinhole and Relative Brightness

01 Apr 2017

http://www.ultraviol...dpost__p__15820

 

See also

A.S.: Pinhole and Relative Brightness

08 April 2017

http://www.ultraviol...dpost__p__15941

 

See also

Andrea B.: Pinhole Test Protocol Summary

10 Apr 2017

http://www.ultraviol...dpost__p__15964

 

 

JMC: Grey Scale Histogram

13 Aug 2017

http://www.ultraviol...dpost__p__17109

 

 

Dmitry: Lens Spectra with Jeweler's Spectroscope

https://www.ultravio...cope-by-dmitry/

 

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Next thing to do: Combine a pinhole test with a uniform white balance application !!!
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Also, there is Enrico's use of the 'Sparticle' or Band Pass Array (as i think he calls it). He has a page of lens tests using that idea.

And also, there were several UV transmission lens tests with diffraction gratings.

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I'll add Enrico and the diffraction gratings as I find the posts. Thanks!
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  • 4 years later...

I have some candidate lenses that I have found and would like test with over the counter household method, but I'm a little lost at these approaches. What I have seen to make me want to test is some lenses that are non-cemented like 5 elements / 5 groups. Of these lenses there are some that I can shine a 365nm UV torch and none of the elements fluoresce. For example a well known Novoflex 35mm f3.5 is used around here, but you can easily see the rear element glows yellow under UV 365nm. I have a several that do not even do that. I would like a super easy way to test them. Even if the transmission is below 50% at 370nm I just want to know what's up. If these have already been documented then I would appreciate the discount of trying those.

 

Can I just take UV photos and see what colors appear, blue, violet, yellow, etc?

 

Or could I set a standard light source and meter the speed suggested for a mid histogram?

 

Here are some of the lenses:

 

Takumar 55mm f2.2 Preset in M42

Takumar 58mm f2.4 Preset in M42. Non Heliar.

Minolta P-Rokkor 75mm f2.5 Projector lens, there are two versions.

Kilfitt Kilar 150mm f3.5 in Exakta. I do not know the lens formula.

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  • 1 month later...

Are there any household items that would reflect the same level of UVA we see in flowers like the violet, blues, yellows and maybe even green?

 

I'm not talking about diffraction grating or pinholes, but actual stuff like common household fabrics, materials or even rocks and minerals. Something textured not shiny of a non-organic cornucopia where I could lay it on a table photograph everything at once and get a similar result as a robust flower. 

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enricosavazzi

UV false-blue is easy, there are types of plastic sheeting displaying a nice reflected UV-blue or UV-violet. UV-white is also common in plastic sheeting. I made a post about two years ago showing both UV false colors: https://www.ultravioletphotography.com/content/index.php?/topic/3403-plastic-fantastic/&tab=comments#comment-28779. For UV black, thick polycarbonate is excellent. For UV false-yellow and false-green, I am not aware of any common items (other than UV-bandpass filters backed with a UV reflector like sanded aluminium) that reliably display them. See the discussion at the above link.

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