Andrea B. Posted August 14, 2017 Share Posted August 14, 2017 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 BoardThere are many examples on UVP. Here are just two.01 Jan 2016http://www.ultraviol...dpost__p__10628 See alsoCadmium: Sparticle vs. Diffraction Grating01 May 2016http://www.ultraviol...dpost__p__12424 Enrico Savazzi: Filter strip for testing UV lenses OlDoinyo: Pinhole and Relative Color11 Jan 2016http://www.ultraviol...dpost__p__10955 Timber: Uniform White Balance and Relative Color16 Sep 2016http://www.ultraviol...ndpost__p__4452 Hornblende: Pinhole and Relative Brightness01 Apr 2017http://www.ultraviol...dpost__p__15820 See alsoA.S.: Pinhole and Relative Brightness08 April 2017http://www.ultraviol...dpost__p__15941 See alsoAndrea B.: Pinhole Test Protocol Summary10 Apr 2017http://www.ultraviol...dpost__p__15964 JMC: Grey Scale Histogram13 Aug 2017http://www.ultraviol...dpost__p__17109 Dmitry: Lens Spectra with Jeweler's Spectroscopehttps://www.ultravio...cope-by-dmitry/ . Link to comment
Andrea B. Posted August 14, 2017 Author Share Posted August 14, 2017 Next thing to do: Combine a pinhole test with a uniform white balance application !!! Link to comment
Cadmium Posted August 15, 2017 Share Posted August 15, 2017 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. Link to comment
Andrea B. Posted August 15, 2017 Author Share Posted August 15, 2017 I'll add Enrico and the diffraction gratings as I find the posts. Thanks! Link to comment
Guest Posted September 4, 2021 Share Posted September 4, 2021 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 M42Takumar 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. Link to comment
colinbm Posted September 4, 2021 Share Posted September 4, 2021 Just take photos with your best 'known' lens & compare the colours & the shutter speed, that is a good comparison. Link to comment
Andy Perrin Posted September 4, 2021 Share Posted September 4, 2021 Or do a pinhole test Link to comment
Guest Posted October 17, 2021 Share Posted October 17, 2021 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. Link to comment
enricosavazzi Posted October 18, 2021 Share Posted October 18, 2021 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. Link to comment
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