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This is a stretch of the forum's general theme as its link to UV is only the recent topic about hummingbirds. This is only partly about visual iridescence. I hope I am forgiven. Last week I was out searching for suitable sites for photos when I stumbled over something I think are very interesting. I had heard about a small nature preserve with bank swallows. When I got there, without any camera, I found a group of nice ornithologists too looking for a more rare visitor, the Bee-eater. They had cameras with fast loong fast tele lenses. The sand bank is fenced off to protect the bank-swallow colony. You have to stay maybe 40m back from the brink. That beautiful bird is rarely seen at my latitudes. It has happened a handfull of times this millennia. It was a privilege just to see the bird hovering in the sky. There is/was a pair feeding small ones inside a deep nest hole in the sand bank. I decided to try to get some images myself. The following day and the day after I got there better equipped and had some luck. The first day the birds only took dragon flies, the second I saw bumble bees, butterflies, and bees in their beaks too. Here are a few of my better images. The last five are from a bird-landing sequence taken at 10 Frames/s Telyt 560/6.8 + novoflex 1.5x extender all images except for the sky image, then Canon EF 400/4.0 IS + EF 1.4x extender

[UV SAFETY] UV-C Light Is Dangerous NEVER look at a UV-C light. NEVER let UV-C light hit your skin or eyes directly or by reflection. UV-C light can cause: severe burns of the eyes and the skin, and DNA damage from broken chromosomes. When working with UV-C illumination, you MUST: cover up completely, wear head & eye protection, and have strong ventilation. Hi, I know this was asked in other threads, but can we make some kind of summary about available UV-C options? To be honest, I can't even find one best light source & filter for this, so I think such kind of topic is needed. I know that there are UV-C light sources like: - low pressure Hg lamps (but are they enough to photograph with, can we have a summary about a distance they are able to lighten so any picture can be made?). - excimer lamps (like 222nm) - aren't they too weak to do any photo with them - I see only input powers but not actual UV-C output when shining at anything from, say, 50cm away? - others? Regarding filters or stacks - I literally find no option. Every filter I see is either just a band-pass filter that only passes 20nm width around some UV-C frequency and then has IR leaks that would make it useless, and if you want to block IR with S8612 then no way - S8612 and similar block UV-C). So I can't find any usable filter, not even speaking about having it in 52mm thread or any similar, they are usually tiny, specific for some laser etc. So can we list possible, most powerful UV-C light sources and possible (if any) filters?

Finished with all the posts, feel free to read and reply Triggered by Kai's thread (https://www.ultravioletphotography.com/content/index.php?/topic/5345-uv-photography-with-a-tilt-lens/), I decided to run some tests of the T/S-lenses. For this, I used the ones I have (17, 24), plus some which I managed to borrow from a friend. I might try to find one of the longer T/S-lenses on ebay, as they are fun to work with. Fortunately, today's weather was overcast, so I managed to get the shots with about the same lighting conditions (at the end I had to hurry else it would have been lightning conditions ). Cameras: UV: Canon EOS 6D, UV b/w by Maxmax IR: Canon EOS 6D, 700nm conversion by Sven Lamprecht VIS: Mobile phone Lenses: TS-E 17mm f/4 L TS-E 24mm f/3.5 L II TS-E 45mm f/2.8 TS-E 90mm f/2.8 TS-E 135mm f/4 L Macro Extenders: Canon Extender 1.4 II Canon Extender 2.0 II I had the cameras mounted on a tripod, but with every change of lenses or filters the position will have changed just a little bit; also I did not take the photos in the order in which I present them, so don't be suprised if there is large change in the field of view. Finally, focussing was a bit tricky (will have to get some reading glasses or one of those magnifying gadgets for the camera), please don't be too harsh. This is especially true for the UV-photos with the 90mm-lens. Five of the UV-shots are takens with an additional S8612 filter, just to get rid of any IR-leaks. I've observered many times, that the S8612 is not really neccesary, escpecially with my Soligor 21mm, but decided to make sure; and indeed, there are couple of shots where there is a difference. Due to the upcoming thunderstorm, I only had time to do a full test in normal-position, plus a couple of tilted or shifted shots with two lenses in UV. I might try another test with my FS-camera in the next couple of weeks, just to see how deep the lenses go into UV, perhaps also some more fun with tilt/shift; but don't hold your breath, work is interfering a lot at the moment. Processing: UV: I only converted to b/w (ooc there is some blueish tinge to the photos) and did global adjustment of exposure, to get the histogramms close to each other. The exposure is noted in the description of the photos. IR: CLiR profile number 5, no further adjustments (there are some differences in the colour casts of the lenses) VIS: nothing If you're interested what's in the photos, it's nothing exciting, just a view in my home-town of Leonding in Austria. Chose this spot because it's not too far away from my place, and it has grass, a field, trees, some buildings, and sky in it. Export was done from lightroom, 1500px long edge, quality 100%. Now, without further ado, the first photo, VIS:

This lens has an old Cooke triplet design, with just 3 elements in 3 groups. It produces bubbly bokeh. https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://www.ttartisan.com/%3FLens/185.html&ved=2ahUKEwjDi8f54NWAAxVdcvEDHYpcAzEQFnoECA4QAQ&usg=AOvVaw2q5PGRTeKkQ3_qzGmvYf4G https://www.techweekmag.com/news/photo/new-ttartisan-100mm-f28-lens-with-bubble-bokeh-effect-unveiled/ A simple design sometimes means deeper UV-reach. Maybe this lens is a good candidate.

The Raspberry Pi HQ camera has shown good results for UV photography. Below a couple of topics in which this camera has been discussed: https://www.ultravioletphotography.com/content/index.php?/topic/3883-raspberry-pi-hq-camera-12mp https://www.ultravioletphotography.com/content/index.php?/topic/4178-uv-safety-warning-reaspberry-pi-hq-affordable-fast-uv-sensitive-sensor Universe Kogaku makes two 6 mm UV lenses, one with a fixed aperture of f/2.8 and the other one with a variable aperture from f/3.5 to f/16. Both lenses cover a Raspberry Pi HQ camera sensor (diagonal of 7.9 mm). The f/2.8 lens covers a 4.8*6.4 mm sensor (diagonal of 8 mm) and the variabile aperture lens covers a 5.2*6.9 mm sensor (diagonal of 8.64 mm). This is the datasheet of the variabile aperture lens: https://www.universeoptics.com/wp-content/uploads/UV0635BCM-1.pdf Also, this lens has a C-mount. These lenses, as the other UV lenses from Universe Kogaku, are not corrected for chromatic aberration. One could rear-mount two 310 nm bandpass filters, to reduce angle-of-incidence effects, if this doesn't degrade image quality too much. One such filter could be this: https://www.edmundoptics.eu/p/10nm-cwl-125mm-dia-hard-coated-od-4-10nm-bandpass-filter/33098/ Of course I'm thinking about a monochrome-converted sensor.

Last Update: 06 March 2015 17:30 GMT: Changed title and added a chart. Just a few notes-to-self about glass. Thought I'd go ahead and post them in case you want an approximate transmission range. Newport: http://www.newport.c...33/content.aspx Sinclari: http://www.sinclairm...s/optical3.html Edmund: OPTICAL GLASS SPECIFICATIONS Fused silica: lenses, optics, high temp apps. Silica, SiO2. Hard, very low thermal expansion, resists high temps. Transmits approximately between 195 - 2100nm Soda-lime: windows, containers/glassware Silica + sodium oxide + lime + magnesia. Easily formed, high thermal expansion, poorly resistant to heat. Container glass has more Al/Ca and less Na/Mg. Transmits approximately between 350 - 2000nm Borosilicate: cookware, chemical reagents, mirrors. Silica + boric oxide + soda + alumina. Fairly hard, low thermal expansion, Pyrex. Transmits approx between 380 - 2100nm. (Is this range for borosilicate B7?) From John Dowdy: Borosilicate transmits quite a bit lower than 380nm, 50% transmission can be depending on the thickness and grade. Calcium fluoride: lenses, laser optics. Fluorite, CaF2. Non-birefringent, high thermal expansion, don't use in hot environment. Low index of refraction, anti-reflection coatings not needed. Transmits approximately between 170 - 8000 nm. Magnesium fluoride: lenses, windows, laser polarizers. MgF2. Birefringent, useful in fluorine environments, moderate thermal expansion. Low index of refraction, anti-reflection coatings not needed. Transmits approximately between 150 - 6500 nm. Zinc selenide: thermal imaging, medical IR imaging. ZnSe. Soft, scratchable, resistant to thermal shock. High index of refraction, needs anti-reflection coating. Transmits approximately between 600 - 16000 nm. Sapphire Transmits approximately between 100 280? - 600 nm? Lead-oxide: crystal glassware and decorative ware. Silica + lead oxide + potassium oxide + soda + zinc oxide + alumina. Dense, elastic, high refractive index, cannot stand high heat. Alumino-silicate: fiberglass, in plastics. Silica + alumina + lime + magnesia + barium oxide + boric oxide. Oxide: fiber optics. Silica + germanium oxide. Very clear. From Enrico Savazzi: Germanium (admittedly, not a glass but a metalloid) was used in the past to make IR lenses. Better alternatives are used today, since Germanium is sensitive to surface degradation. It transmits well between 6.5 and 13 micrometers (not nm), but has several narrow transmission windows also at shorter wavelengths. Schott WG Glass: See later posts. Looks good. Here's a nice chart from Edmund Optics: Link to Original Page (More charts in posts below.)

Tilting the depth of field has been a method used in architectural and landscape photography since the early days of photography, in order to be able to image areas of the foreground and background sharply at the same time, especially with large film formats and long focal lengths. Theodor Scheimpflug's name is often associated with this method today. Early field cameras and cameras based on the principle of the optical bench provided the necessary mechanical requirements. Modern (digital) cameras require special tilt lenses or tilt bellows devices. An alternative that is used intensively today and does not require such special accessories is the focus stacking. Particularly suitable for UV photography with system cameras is the use of a tilt bellows (e.g. Yashica), which is combined with a UV-transmissive enlargement lens head. Today I would like to present the variant that does not require any handicrafts or adaptations. I simply combined my Canon EOS 6D-FS (UV sensitive up to approx. 365 nm) with the Canon TS-E 90mm 1:2.8 (the old non-L version). For filtering I combined a ZWB2 with 2 QB21. Even without post-processing, all images show very good sharpness and excellent contrast. I slightly increased the color rendering. In addition to grass, Glechoma hederacea (violet flowers in the VIS, colorless dark in UV), Bellis perennis (white leaves and yellow center in the VIS, blue with a dark center in the UV) and Ranunculus acris (completely yellow in the VIS, yellow edge with dark center in UV). Both shots were taken from a tripod at f/8 and 3200 ASA. The exposure time was (in the evening when the sun was low) 0.7s. The other two images show a violet potted plant in the VIS. When shooting at aperture 11, once the plane of focus through the flowers, in the second picture with the plane of focus tilted for maximum blur in the background.

The glass types used in camera lenses are the main limitation for UV reach. Flint glasses are generally the worst for UV transmission, and very dense flint glasses start absorbing already in the blue-violet portion of the spectrum, and look visibly yellow. If the glasses used in a lens are known, as well as their thicknesses, one can roughly calculate how deeply that lens will transmit UV, and most importantly one can know in advance which lenses wouldn't work. This ignores coatings and optical cement, of course. On this website (written in Italian) one can see various drawings of lenses with the glass types shown: https://www.nocsensei.com/

This lens is similar to the previous one, but has a longer focal length and is better corrected. Like the previous lens, it is not corrected for chromatic aberration. The focal length is about 55 mm, and the maximum aperture is f/2.8. Optical scheme: Lens at f/2.8, ray angle of 14° (covers APS-C): The lens actually covers larger sensors, at the expense of vignetting and barrel distorsion. Here's a 30° ray angle: At close focus distances (here 150 mm), some field curvature emerges: Lens at various apertures, 14° ray angle, infinity focus: There's plenty of space for the aperture, and also there's room for an helicoid at the rear. The most challenging part is the 0.5 mm gap between element 2 and 3.

Finalized: Work in progress. Last Update: Nikon 80mm f/5.6 EL-Nikkor:. old metal version Manufacturer: Nikon Manufacturer's lens designation: EL-NIKKOR 80mm f/5.6 Currently manufactured: No Lens type: Enlarger lens for film up to 56mm x 72mm ( Ø100mm ) Focal length: 80mm Aperture range: f/5.6 – f/45, Manual, 8 blades Design: 6 elements in 4 groups Flange Focus distance: 70mm Recommended magnification range*: 0.067x – 0.5x. Optimal magnification *: 0.2x Mount: M39 x 26tpi thread + hidden 32.5 x 0.5mm thread behind a built in step ring. Sensor format/coverage: up to 56mm x 72mm ( Ø100mm ) at 0.2 x magnification Front filter: 34.5 mm x 0.5 mm Introduction year: pre 1960? S/N of test object: 933700 * Definitions reversed from normal enlarger definition, referring to the motif not the negative-plane Lens review (VIS), on the web: Lens Manual on the web: http://www.savazzi.n...El-Nikkor_2.pdf Image of test object: Unfortunately the lens is buried and hidden by my DIY focussing and aperture-control build. It was too difficult to disassemble for any photos. Except for the text on the front ring this lens looks almost identical to the older EL-NIKKOR 80mm f/5.6 Nippon Kogaku Japan presented here: https://www.ultravio...pan/#entry41477 Transmittance Summary Definitions of the parameters below Range: The El-Nikkor Old Metal lens transmits 0-70% in an increasing slope from 310 nm to 400nm. TVISmax(%) = 73% T400nm(%) = 70% T365nm(%) = 60% This high percentage is an indicator for relatively short exposure time under typical UV-pass filtration peaking around 365 nm. λUV HMvis(nm) = 341nm λUV HM400(nm) = 340nm λUV Zero(nm) = 311nm These three values indicate that the lens is working even for some upper UV-B photography with some filters and a few for this, suitable cameras. Spectral transmission graphs: UV-NIR, EL-NIKKOR 80mm f/5.6, old metal version The transmission measurement accuracy into the end of NIR range is less good due to limitations in the light source. UV, EL-NIKKOR 80mm f/5.6, old metal version UV-Log, EL-NIKKOR 80mm f/5.6, old metal version General comments about the UV-reach: reach Filters and how to use them on this lens: The front filter thread is rather odd, but suitable adapter can be found at RafCamera: https://www.ebay.com...amera?_bkw=34.5 It is also possible to use rear mounted filters, either in lens mount adapters for mirrorless cameras like Sony A-series etc, or placed directly in the camera. An alternative, if space in the camera allows, is to putty-mount a filter directly against the lenses rear element mount ring. The rear lens element is recessed and thus safe and the ring provides a good reference plane for orienting the filter normal to the optic axis. My Omega 330W80 Improved Ø25mm, is mounted in a 27mm-filter ring and works well to mount as it is. Handling and focusing: This lens needs to be combined with a helicoid or macro bellows to set desired magnification. With short enough minimum length of those it is easy to obtain focus at infinity even for DSLRs with long back-focus distance. https://www.ultravio...__fromsearch__1 Flare and sun-stars: NA Sharpness: I have found the lens impressing sharp all over the image field, but have no actual measurements. My main usage has been for closeup UV and UV+VIS photography. Lens distortion: The lens Chromatic Aberration / fringing in UV: CrA Image samples: UV: Filter: UV, Fringing: Filter: UV, Fringing 100%: Filter: VIS+NIR: Filter: NIR: Filter: long pass 800nm

I have lately bought a few more Canon TS-E lenses to complement the TS-E 24mm I got a long time ago. My goal was mainly to use them for NIR Photography. After my last published topic Kai asked for information about the UV-reach. https://www.ultravioletphotography.com/content/index.php?/topic/5846-a-visit-to-borgeby-slott/#comment-62641 Here is the result of a sloppy quick test without a high power light source and integrating sphere. I just used a collimated beam from my deuterium light source and then scaled the graphs "to taste" to a level I guess is reasonably correct. The measurements as usual made with my Ocean Optics Flame wide-band UV-VIS-NIR spectrometer. Due to the truncated light-source there is only valid information up to the violet band. Here I only present a narrow wavelength-band with the valid information in the mid part. Tested lenses and their graphs are Canon TS-E 24/3.5 L. Purple Canon TS-E 45/2.8. Red Canon TS-E 90/2.8 Black It seams like all three lenses are marginally usable for UV, but that the TS-E 90mm is best.

Not sure if this is appropriate here, but the pics were taken in UV, so I'll give it a shot. Here's a number of photos I took with my b/w-uv Canon EOS 6D, internal X330C-filter, external S8612, EL-Nikkor 105mm on extension tube, full-spectrum Yongnuo YN560-III handheld, triggered by remote-trigger on the camera. I was aiming to illuminate only a small part of the object, so quite a number of misses until I got the desired effect. The camera was also handheld, on purpose, I didn't want to have tack-shart photos, but a bit of blurriness, perhaps dreamlike, where you only see bits and those are not quite clear. Processing, apart from cropping to square format, was minimal, just here and there reducing the highlights a bit. I did try to invert them as well, turning low-key into high-key, but most of them didn't work, just one or two, but the mood is completely different, of course. (the white snow-drop is not an inversion of the black one, it's from a slightly different angle) I am not sure how different the plants would have looked like, had I used a VIS-camera, but I think that UV did accentuate the surface structure - it usually does, after all

Do we need a dedicated lens design section? Here's a lens I designed using WinLens3D Basic. The optical layout was inspired by Llewellyn Optics's 6 mm M12 lens available on MaxMax site. Link: https://maxmax.com/uv-lenses/lenses Here's the design posted on the site: My lens uses Thorlabs elements, all made of fused silica (the lens is not corrected for chromatic aberration), and (barely) covers an APS-C sensor (judging from the ray tracing graphs below I'm guessing the corners would look dark). The software gives an image distance of 31.7 mm (I'm guessing this is the distance between the rear element and the sensor). Here's the optical layout: Below the ray tracing drawings. Maximum ray angle of 35°, object points set at linear height, but are not projected linearly by the lens, they are "squished" at the edges, thus there's probably barrel distorsion. f/1.4: f/2: f/2.8: f/4: f/5.6: f/8: I would say the lens is kind of usable from f/2.8, and should be quite sharp from f/5.6. Probably the biggest challenge in building it is fitting an iris in that tight space. As for the focal length, I don't know where to read it. I could work it out from the aperture, but at this point I'm not sure about what the software is doing. Here's some information: I posted large images, hope it isn't too confusing. I can re-upload them if necessary.

This YouTube channel (https://www.youtube.com/@invisiblerays) has some videos on UV/IR photography. The latest videos uploaded show footage taken with Universe Kogaku lenses. These lenses have been already discussed on UVP, for example here: https://www.ultravioletphotography.com/content/index.php?/topic/4784-uv8040bk2-does-it-make-sense These lenses are not chromatically corrected, as they only use one type of glass (fused silica), thus they need to be refocused when changing wavelength. From the videos below, image quality looks to be pretty good, and there's not much chromatic aberration visible (I can't see any of it). They offer lenses from 6 mm to 105 mm, but only lenses from 35 mm cover an APS-C sensor (actually not, as the diameter of the image circle is 22 mm, which is the side, and not the diagonal, of a Canon APS-C sensor, but maybe they cover a few extra millimeters). Two videos: https://youtu.be/6Rok76Quulk https://youtu.be/NvtFJsU8bTM

Browsing YouTube I found this video: https://youtu.be/TlsS3rUjg8c [the site is acting weird, at least on my PC, so I cannot embed the link] The uploader warns not to watch the video as it is boring, and I haven't watched the lens-building part. What I find particularly interesting is the beginning of the video. It shows a modern f/0.95 lens next to an older f/4 enlarger lens in UV. The enlarger lens doesn't show any false color, and the modern lens has a lavender tint, as expected. But actually it doesn't look too bad, and it seems to transmit a surprising amount of light. Maybe some f/0.95 lenses could be interesing for UV photography if deep reach is not a priority.

The OMDS M.Zuiko 90mm f3.5 macro pro lens is launched today - much YouTube marketing stuff but no transmission profiles that I could find. For Oly shooters, this lens seems to be best for visible macro field work, or just normal mid telephoto as this is micro-four-thirds and 35mm equiv is 180mm - claims you can do handheld focus stacking in camera, but we shall see. Probably really good for UVIVF at night outside. It accepts Oly 1.5 and 2.0 teleconverters and STF-8 ring flash. Claims about 10 cm (4 in) minimum focus distance. I will bet that it doesn't pass UV, but will see when it comes next month. I did order it as I do a lot of flower closups in the visible for teaching. Nice thing is that the filter size is 62mm, which is the hot mirror size I already have for my normal vis photo zoom lens. More when it comes.

I have found a software-tool for setting up and planning for photo stacking (not macro) and using Tilt-shift lenses. The Lumariver Depth of Field Calculator : https://www.lumariver.com/lrdof-manual/ It is also usable to set up an optimal hyperfocal-distance setting or optimal DOF for one shot. The tool is very powerful and maybe a bit difficult to grasp at first, but after a while it becomes increasingly more helpful and easy to use. I am still learning more each time I open the app. There are several tutorials on the site.

INCOMPLETE Asahi 85mm f/4.5 Ultra-Achromatic-Takumar Manufacturer: Asahi Optical Co., LTD, Tokyo, Japan Lens Label: Currently Manufactured: No Note: There are 2 models. And we need to look up the history. Lens Type: short telephoto, manual focus, aperture preset Lens Design: 5 elements, 3 fluorite + 2 artificial quartz Focal Length: 85 mm Aperture Range: 4.5, 8.0, 11.0, 22.0 Correction: 220 - 1100 nm This lens could be focused in Visible light prior to adding a UV-pass or IR-pass filter. In digital Live View, focus can usually be made on screen if the aperture is set wide open. Format Coverage: 29° Minimum Distance: .6 m = 2 ft Magnification: Mount: M42 x 1 screw mount Helicoid: Yes Flange Focal Distance (FFD): 45.46 mm The lens can easily be used on any camera with an FFD shorter than 45.46 mm by means of a mount adapter. Front Filter: 49 mm Sharpness: Transmission: Our member JMC has kindly provided us with a comparison chart for the Big Four dedicated UV lens. This topic's UAT lens is the green line.

Not sure where to put this, and also not sure, if anybody's interested in this: https://www.forgottenbooks.com/de/books/PhotographischeObjectiveundOptischPhotographischeHilfsapparate_10595978 If it's inappropiate, feel free to delete this. If you're interested, better be quick, it's only up for free today.

OM is releasing a new 90mm macro lens for Olympus bodies next year. I use the excellent Oly 30mm macro for UV flower shots, and could use a little more working distance. Unfortunatley my old Oly 90mm macro (used for years in visible range) does not pass UV. Does anyone have any insider OM skinny on the transmission for the new 90mm lens? I've tried asking OM and get only "we will let you know after release" kind of response. If the older 90mm does not pass UV, can we assume that the new one has a similar construction and will also not pass UV?

Minotla W.Rokkor-QH 21mm f4 — Biogon type Rangefinder ultra wide-angle lens | by LI Sam | Rokkorxblog | Medium This looks like a cool lens, very old but has 8 elements in 4 groups. actually used on old slr's with mirror lock up. above website shows decent performance on sony ar7II. there is also the nikon 2.1cm f/4 and a contax 21mm rangefinder lens that would be great to test. they are pretty expensive though typically around $300-$400. there is a minolta one on ebay for $200 now.

UV SAFETY] UV-C Light Is Dangerous NEVER look at a UV-C light. NEVER let UV-C light hit your skin or eyes directly or by reflection. UV-C light can cause: severe burns of the eyes and the skin, and DNA damage from broken chromosomes. When working with UV-C illumination, you MUST: cover up completely, wear head & eye protection, and have strong ventilation. It is hard to find lenses made specifically for UV-C. But for some years, 254nm was the main wavelength used for printing transistor and microprocessor circuits on silicon wafers. These were made to have perfectly flat fields, large apertures in order to avoid diffraction, and extremely high resolution. To achieve the highest possible resolution, these lenses are optimized for a single wavelength. These lenses could cost hundreds of thousands of dollars (their more modern replacements cost millions). They were among the most perfect lenses of their time, and they could use very exotic materials. Sometimes these come up for sale on eBay or industrial salvage sites. That's how I got this Tamarack Scientific 254nm 1/5x reduction lens. The lens alone weights 10kg!

While discussing a problem with filter retaining ring replacement, I saw again this Amazon link from our member Enrico. It brings up some rubber filter wrenches which can be very useful if you have ever needed to dismantle a lens or any of its parts. Then if you scroll down the page, you see other tools like the wrap-around filter wrenches, the metal spanner wrenches and a nifty set of camera screwdrivers. I'm not sure how long this link will last, but here it is. Lens Tools Link [Our usual disclaimer: UVP, Andrea, and Birna are not affiliated monetarily with any commercial website and gain no benefit from any member's purchases.]

Gear used: Olympus e-pm1 body full spectrum converted myself. Lomo T-43 triplet lens. More details in index topic Sun, no filter Quartz lamp, no filter Quartz lamp, qb21 Quartz lamp, zwb1 Quartz lamp, zwb2 Quartz lamp, zwb3 UV black U-tube, no filter UV black U-tube, zwb1 UV black U-tube, zwb2 UV black U-tube, zwb3

I have Sigma's 30mm f/1.4 DC DN lens and it passes UV well enough for flower portraits. But in search of more working room I saw a Sigma 56mm f/1.4 DC DN on B&H. B&H specs says that the 30mm has two aspherical elements and one special low dispersion (SLD) element, and the 56mm has two aspherical elements and one high-refractive index element. The similar number of elements in the 56mm seems like it might pass UV, but I don't know if the asphericals are the same, or if the HRI element in the 56mm would prevent it passing UV. Has anyone tried to use the 56mm?