Search the Community

I recently received a Convoy C8 365nm LED flashlight from yooperlites.com. It has the extension for loading two 18650 batteries, with preinstalled ZWB2 glass filter. I'll try it outdoors when I have the time, but for now, I can see that it easily outshines the Convoy S2+. Also, I've noticed that 'Way Too Cool' sells much the same product, boldly claiming US Patent rights for installing ZWB2 glass (or any color filter glass) on any Convoy C8 flashlight. Not sure what that's all about, but it appears to have the same specs as the Yooperlites version. I was sent a free Yooperlites sample. photo: Olympus TG-4

Hello. Today I have decided to test a few different lightsources that emit UV intense enough to take pictures with: -BeamZ 25w UV Blacklight compact fluorescent bulb -Repti Planet UVB 15.0 compact fluorescent bulb -Domáce Slnko UVIR (a potentially dangerous home tanning machine from probably the 70s or 80s, more info here) -full spectrum Speedlite 199A (very similar to sunlight) -Alonefire H42 12 core 365nm LED torch (a UV blacklight with a decently wide peak) I set up the following scene: Here you can see: -a filter case (background) -a PTFE sheet -a uranium liquor glass -a ZWB1 2mm thick filter -a carrot and an apple set on a white ceramic plate And here are the results, left side is color balanced on the PTFE, right side had color balance turned off in Darktable. Rest assured, I followed basic safety, tried to get exposed to the lights as little as possible and wore yellowed protective goggles. The UVIR discharge lamp briefly smelled a little like bleach when turned on but stopped rather soon. I have no idea if that's the smell of ozone and if it emits UVC, but I ventilated the room well afterwards. The UVB light is safe to get exposed to for short periods of time according to reptile forums which I consulted, even then, I only exposed myself to it briefly. I must say the UVIR discharge lamp also looks really scary when turned on, it emits really intense ghostly blue shine, it also takes a while to reach peak output but when it does, it might be the strongest UV source I've ever handled. If it was collimated it might produce shorter exposure times than those available while outside. Overall, when I briefly tried the UVB light yesterday, I was rather disappointed as it didn't look green at all, which I expected, and relative to sunlight it produced a yellow shine that was almost identical to how I remembered the fluorescent blacklight's shine, however, it turns out it produces much more colorful results, perhaps even a bit better than the sun, since the ratio of 365nm to UVB is skewed more towards UVB. The Speedlite 199A which produces a spectrum very similar to sunlight shows way less color. I also plan to sand down the reflector on my table lamp that I screw the bulbs into, as the white paint it is using right now is not very UV reflective besides the 390-400nm region, at least that's my guess due to the fact that it appears very purple in sunlight. Currently I just taped some aluminium foil to it, but that's far from ideal. Next I would like to try the Exo Terra UVB 200 25w, which should be even more powerful, but I'm not sure it can get much better than this.

I like the fan shaped round reflector. No plastic diffuser to filter out UV. Price is great. Not a fan of the battery arrangement. Don't some of the Godox work well for UV? Anyone think this one has potential? https://www.dpreview.com/news/3602160276/godox-s-lux-senior-is-a-larger-more-powerful-flash-with-a-retro-inspired-design Thanks, Doug A

[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. I have investigated & invested in a Safer UVC, Excimer 222nm Lamp, with Filter. The filter is essentially clear but blocks the nasty UVC of 254nm up to around 300nm, but unfortunately has a leak from 300nm into near IR, peaking at 450nm. First photo is of the gear. Second photo is the output from 250nm to 850nm. Third photo shows the blocking of the dangerous UVC 250-300nm.

Lens test with 365 Led Light 365nm (with ZWB2), above is the outline of the set and a photo with nothing lens two good APO lenses covering the 4x5 "format It seems to me that Apo Ronnar is the best (you can find it with and without shutter at a good price)

It has a slight bronze tone that would appear so. I ask because I just got it in an online auction and wanted to line up an uncoated tube if it is coated.

[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. I have some UVC fluoro tubes that have filters about 200mm long, & I would like to concentrate the light from the UVC fluoro tubes to a 50mm spot light, & keep the full output of the tube ? How is this possible please ?

Hello, I've seen the somewhat famous macro photographer Micael Widell recommend using the ReCyko Pro Photo Flash batteries with your external flash since it can enable it to fire more reliably and faster. I was wondering, would this improve the rather slow recharge times of my full spectrum 199A? I currently use it with these batteries. They work fine but I get to fire the flash every 7 seconds or so, which is not that great. Here's a link for the type of batteries I have in mind. https://www.amazon.co.uk/GP-ReCyko-Photo-2600mAh-Rechargeable/dp/B0785N2XVC What sort of improvement could I expect? If it's marginal then I guess I don't really care, but if they allowed me to fire say, every 4 seconds instead of 7, it would help a lot, especially when I want to illuminate bigger subjects. Thank you.

When I started UV imaging about 5 years ago, I ended up having to buy various bits of kit, not knowing what would work and what wouldn't (some might say not much has changed there.....). One lighting setup I got was a UV modified Nikon R1C1 flash system. Advanced Camera Services (where I bought the UV modified camera from) replaced the flash windows with UV transparent material, but it blocked the visible. I think at the time, I assumed that I needed the flashes to be visible blocking rather than just leave them as emitting everything. However, the other lighting I had worked for the project, and this modified R1C1 has sat in a box ever since. Until yesterday. I decided to get some shots with this using my UV modified d810 and Rayfact 105mm UV lens. Subject - wild flowers in the garden. Lighting - mixed, daylight, but mixture of sunshine and shade. ISO2500, f11 to f22, whitebalanced in Darktable and reduced in size for sharing here. The images; I can't remember what the material was that they used on the flashes, but it wasn't their UV filter for the camera. I guess it is UG11 or the ZWB equivalent. Using the flash gave about 3 stops more light than just sunlight. Unfortunately the ISO is still too high for my liking, but it makes for a usable handheld UV setup for out in the field. It does look a bit outlandish though; I suppose with the flashes being modified in the way that they have been, if I ever get a normal unmodified Nikon camera, I could use them for closeup fluorescence work.

I like to go to flea markets, looking for lenses, cameras, old film, curious lightsources, objects that might be interesting to photograph and more. I went to such a flea market on this saturday, and I found something that really caught me off guard. It's a do-it-yourself tanning machine. Came with a box, a power cord, a pair of deep red glasses and some pamphlets. It's a square device with a pop-up stand, a huge reflector that houses two ceramic rods and a discharge lamp. The writing on the discharge lamp reads "TESLA RVK 125 W" and on the other side "MADE IN CZECHOSLOVAKIA". Obviously, I had to try turning it on. It works just fine and it was a sight to behold. I obviously did not leave it on for very long as to not expose myself for very long, since this seems like it's likely to be a powerful UV-B emitter. My total exposure ended up being hopefully below 30s, my hand got the most since I eventually had to reach in and turn it off when it was in full swing. I had my polycarbonate prescription glasses on and I obviously did not stare at the thing so hopefully fine on that front too. The image above shows the brightness in the early stages. When the discharge lamp really gets going, it becomes blindingly bright, and the rods get scorchingly hot, almost like an open flame, I suspect them to be powerful far IR emitters. Last interesting thing is the UV shade this device produces. It's very greenish, hinting at a likely UV-B bias. First image is color balanced on daylight, the other one has color balance turned off. I have no idea what gas could be inside the discharge lamp. Hopefully it's not mercury in case the discharge lamp was fused silica. That would make this a UV-C lamp. But I don't think people back in the day would use technology that dangerous on themselves. This is probably from the 1980s, not the Victorian era. I will be getting myself some 100% cotton overalls to see if this is any good as a UV source for photography. Only problem will be the IR which will inevitably heat up anything I point this at.

Editor's Note 09 May 2022: See also Test #2 below. LINK Editor's Note 09 May 2022: Title changed for clarity and information. Tag added. I'm writing this here so I will be reminded to go do this experiment. I get trapped in garden restoration, laundry, and all sorts of boring stuff. Now I will see this everyday and feel guilty enough to go and actually do the experiment. Right after I finish transplanting the Columbines. TEST #1 Gear: UV-cam UV-Nikkor 105/4.5 UV-flash: Nikon SB-140 which has removable UV and IR filters. UV-pass filters: U360 stack, BaaderU, SEU-Red Procedure: For each UV-pass filter, make a reflected UV photograph under the Xenon flash both with and without the UV-pass filter. Question: Are there any differences between the two photos? I'm thinking it would be useful to perform this Experiment both indoors and outdoors in good sunlight. Comments and suggestions welcome, as always.

Finding a good battery for a torch can be tricky as there are very many bad quality batteries out there. I have found an excellent site that has reviewed many different battery types in a serious way There are comparison tools for different battery shapes: https://lygte-info.dk/review/batteries2012/Common18650comparator.php https://lygte-info.dk/review/batteries2012/Common26650comparator.php To use the tool for a general comparison between batteries, to find a good battery, just look for a curve with a high level that stretches far to the right wit a reasonable current load. You will find that some batteries labeled with high Ah-numbers are just fakes. To use the tool for a specific torch you need to know a few things to interpret when the battery starts to affect the output. I'll use the Nemo as an example as we knot a few facts about that torch. It is built with constant current driver ICs that keep the light and LED-current constant until the batter-voltage gets too low. That limit is around 3.7-3.8V. With a battery voltage above that the current is ca 1.8A. The torch uses 26650 LiPo batteries. Choose a battery in the comparison tool for that battery size. Check the checkbox for 2A that is reasonably close to 1.8A and uncheck all the other current-checkboxes. Find the point where the curve passes below 3.7V or 3.8V and read the Ah value under the X axis. Divide that value with the selected current (2A) to get the time the battery can deliver a constant light intensity. The Samsung INR21700-50G 5000mAh (Green) https://lygte-info.dk/review/batteries2012/Samsung INR21700-50G 5000mAh (Green) UK.html pass 3.7V after almost 2 hours and will keep up the light intensity for an hour.

Here are the unedited raw composites of a red Penstemon flower which I photographed last summer using a Nikon SB-140 UV-flash and then a filtered Convoy S2+ UV-Led. As you would expect the UV-Led produces a more monochromatic image. But not by much for this particular flower. I sampled the raw colors in 4 places to find their location on the color wheel. Then I made a labeled dot of the color at full saturation and brightness. The UV-Led raw colors are red-orange. The UV-flash raw colors vary from red to red-orange. Please remember that these raw colors are just for this particular example. Other subjects might or might not show more raw color variation. Out of curiosity, I applied an average white balance to a small square over the flower and part of the background. The UV-Led photo shows less false color than does the UV-flash version. I'm just observing, not making any claims here. I've seen false color in UV-Led photos, just not this particular one. The UV-Led version seems to have a bit of blue noise? [Side Note: The flower moved a bit between the two exposures. I see that the UV-Flash version is slightly OOF on the flower's anthers. I also see that the UV-Led version is a bit too dark in the flower's throat. I could have directed the UV-torch a bit better.]

https://www.instructables.com/Make-It-Glow-a-Flash-Upgrade-to-Ultraviolet/ The nice thing about this speedlight conversion is that it uses round pre-mounted filters attached via duct tape and a step ring. This should cost a bit less than it would to get rectangluar pieces of filter filter glass cut to size. What I cannot assess, of course, is how strong the UV output is. Please note the warnings about speedlight capacitors.

When I was out shopping today I saw something that might be used as a flash reflector material. It was a roll of a rather thin material intended to be used on a car's windsheeld, both to reflect heat and avoid removing frost and snow in the winter. Very cheap, around 3€, so I bought two, just in case it turned out to be suitable. I found it in a German based shop Lidl. That company have shops all around Europe and some of the gadgets they sell has a surprisingly high quality. To reduce specular reflections and deep shadows special light boxes are often used for product photography. I have been considering doing this in my macro setup with my UV-converted Godox flashes. One potential problem is to find a material that have a good reflectance reasonably deep into UV. When I got back I promptly set up my spectrometer for reflectance measurements. The light source I used was the deuterium lamp in my DH-2000-BAL emitting light between 200nm and 430nm. The light source was coupled to two different measurement heads via 600µm UV-VIS fibres. The first measurement head for diffuse reflectance directs a collimated beam to the test object and the scattered light is averaged in a small integrating sphere. The second measurement head detects the reflected light at a 90° angle from the light of the light source, while all internal walls are matted black to cancel any scattered light. The measurements were individually calibrated for dark spectra and against a matted PTFE sheet as a 100% reference. I do not have a suitable specular reflectance target so that had to be good enough. The results looks like this: The Specular Reflectance measurements did as expected result in different levels depending on how the uneven material surface directed the light to or away from the detection fibre. I kept two of those measurements as they had a better signal to noise ratio, for a better cutoff wavelength readout that was 312 nm. That agrees well with the Diffuse Reflectance measurement. It is difficult to tell the exact cause of the drop below 320 nm. The plateau below 308 nm might be due to internal scattering/crosstalk in the spectrometer and the reflectance here might even go to zero even if the graph show something different. As this shortwave range is not of much interest for me, I did not investigate further. For my purpose this material is usable.

Today I would like to report something about UV sensitivity and the color differentiation of my camera bodies. First to the cameras: It is a Canon EOS 500 D (in Japan EOS Kiss X3, in North America EOS Rebel T1i), an APS-C camera with approx. 15 MP, and a Canon 6 D, a full-frame Camera with approx. 20 MP. I de-filtered the 500 D according to the instructions from Gary Honis (http://dslrmodifications.com/rebelmod450d1.html). As a replacement for the removed filter, I used a quartz cover glass from microscopy (cut to size). The 6D I had de-filtered professionally (http://www.astro-modifikationen.de). The filter structure of the 6 D is more complex. Only the top two (dust vibrator and original white balance filter) of the three filters were removed. One protective glass remains on the sensor. Unfortunately I have neither a calibrated spectrometer nor a suitable monochromator for measurements. Of course I am interested in individual measurement curves for filters and lenses as well as sensitivity curves for sensors, but – on the other hand - for photography only the interaction of all parts is relevant to me. This is why I have chosen the following method for my comparisons, which comes very close to the real situation when photographing in sunlight: I used the midday sun as a light source. The light falls through a slit onto a grating (made from a DVD). I then focused the spectrum generated in this way through my UV filter (here: Baader-U) and the lens (50 mm magnifying lens, mounted on a suitable helicoid) on the camera sensor. The spectra can be seen twice each, above with the camera-internal white balance to sunlight, below with white balance from reflected sunlight to matt PTFE. So I can see which parts of the sunlight are used in which intensity for the picture (with a white motif) and which wavelengths correspond to which false colors. The Fraunhofer lines disturb the overall impression a little, but also allow an internal wavelength calibration. Canon EOS 6 D-FS Canon EOS 500 D-FS Conclusions The sensitivity of the EOS 6 D-FS does not reach as deep into the UV range as the 500 D-FS. This is probably not due to the sensor, but to the remaining filter glass. The color differentiation is stronger with the 500 D-FS. The longer wave range is shown more violet with the 500 D-FS and more bluish with the 6 D-FS. The shorter-wave area is shown greener on the 500 D-FS than on the 6 D-FS. Overall, with this method I can clearly see which filter-lens-camera combination can display which UV area. In further posts I can show lens comparisons and comparisons with other light sources.

These days one can find plenty of "full spectrum LEDs", also described as "380-840 nm LEDs", on multiple online auction sites including Amazon and eBay. See for example a "full spectrum 380-840 nm" 10 W cob on Amazon (https://www.amazon.com/Chanzon-Spectrum-380nm-840nm-Components-Hydroponic/dp/B01DBZK3V6 ) and plenty of similarly described single LEDs from 3W and up. The purpose of this heads-up is to warn that these devices are not the full-spectrum LEDs that several of us have been waiting for, to use as LED illumination sources emitting UV and VIS, and a little NIR as a bonus. I have not tested any of them, but from the information one can glean from the ads they are not what the name suggests, but 380 nm UV LEDs embedded in a resin mixed with a phosphor that emits in the red, deep-red and NIR range. Possibly there is also another phosphor in the mix, emitting in the range across the UV to VIS borderline (mostly purple and blue), but I cannot know for sure without testing these devices. In any case, their emission is not even remotely "full spectrum", but has a primary peak in the UV and possibly blue, and a broader and lower secondary peak in the red and deep red, possibly with a tail in the nearby part of NIR. There is most likely little or nothing in the rest of the VIS, as well as below 380 nm. These devices are an extension of the well-known "LED grow lights" sold for over two decades, originally equipped with plenty of red power LEDs mixed with a few blue LEDs. The red light is well known to stimulate photosynthesis in virtually all plants, while the blue light and/or NUV supposedly stimulates flowering of some plants (exactly which plants I will not discuss here).

I can't remember whom now got me looking at brackets again. But I found a cheap ring bracket off Ebay and then started to modify it to finally build the 4 light Canon 199A flash thingy I have wanted for a long time. I added some 6" x 3" L brackets, and some hot shoe triggers with pc sync ports on both sides, so that I don't need splitter cables, like I originally thought I might need. Hopefully you can make it out in these images.

I am wondering about a 500+ ws unit that either comes with a quartz tube or can be easily converted. I saw that the Godox AD600BM was a disappointment. Are there any good new options, or is used the best approach?

I figured I'd try out the UV Beast 365, not bad for a tight beam. Went outside with it tonight, and was surprised how snow absorbs the visual light and fluoresces things on it and in it. All shots were iso200 and varying .5-1sec f5.6 Canon 77D FS, clip in uv/ir cut 1.25 filter (never planed on doing visual again just used one I had laying around), Rokinon 135 F/2 UV Beast V3 Pretty cool what the wind storms have left in the different layers of snow Lonely leaf in it's Winter journey Sea shell fluoresces really bright, something you find in the snow everyday Under exposed snow because of the shells brightness

LED torches lack the colors of sunlight and flash. Does anyone make a torch with multiple UV wavelengths to address this? Thanks, Doug A

My whiz-bang Kolari Vision flash set arrived today and although my UV filter hasn’t arrived yet, I couldn’t wait, so shot an IR “test “- sort of, considering this non-vis rookie has never shot any IR before….sooo, see below why is my IR as-shot pink? First impression of the flash - the dang thang is almost bigger than my camera. Not what you’d call “handy”, but it has a lot of bells and whistles. I like the idea of having a multispectrum flash in the field, plus the two little focus assist flashlights (UV and IR) are going to be handy. The flash power is pretty stout - light power adjustments and EV adjustments both take some experimentation. I shot consistently one stop over exposed in TTL. Just a start though. I’m used to itty bitty Olympus macro flashes, so this bad boy is a new thing for me. There is a general description of the flash here https://kolarivision.com/kv-fl1-flash-light-the-invisible/. Camera: Olympus EM-1mk2, Kolari full spectrum conversion. Lens: Sigma 30mm DN (60mm full-frame equivalent) Filter: Hoya R72 for IR, Kolari Vision hotcut pro 2 for Vis. Flash: Kolari Vision KV-FL1, with IR cup (850nm) Subject: random sunflowers and daisies from grocery store, probably this time of year in Texas sourced from Columbia #1 Visible, no flash (all these shots are F11.. auto ISO chose 6400 for all of these shots - normally I wouldn't go that high, but the visible didn't look too bad I think. Now I switched to the R72 IR filter and used the Kolari Vision flash with the IR cap. Soooo, why is it pink? I am probably making a baaad rookie mistake(s)? This is as-shot. Details a bit blown out. I wasn't wild about the pink.. expected white... so in Lightroom I threw this pink mess into Nik's Silver Efex.. much better. As-shot, using Silver's neutral preset. Now I'm taking the flash outside to find a cooperative cow to shoot in IR :-)... pink cows maybe? Lots to learn.....

Halogen bulbs emit a low but detectable amount of UVB light. Here I recorded UVB at around 310 nm. Full-spectrum Canon EOS M, SvBony lens (more detail here), double Chinese 310 nm bandpass filter + 2*2 mm thick ZWB1 filters. The bulb, which is supposed to run at 12 V, has been powered at 16 V. I extracted the green channels only from the raw images. Lens fully open (about f/2.2), ISO 100, 15 s exposure: Lens stopped down (about f/4.5), ISO 400, 15 s exposure: I can tell I recorded UVB only (without contaminaton) for two reasons: the raw color is green (as I have obtained from a 310 nm LED, for example) and a magnifying glass, which I know it's transparent down to at least 340 nm and it's opaque at 310 nm, completely blocked the light.

So I accidently ordered a Canon 155A first then went and ordered a 199A. Well the 199A didn't work even after cleaning all the contacts, might tear that apart later. So the 155A flashes, but everything I tried, it won't connect to my 77D on the hotshoe, but fires manually when shorting the contacts. I imagine the camera does that automatic when matched. I have no clue what I need to make it work so rigged a switch, only thing is getting the timing perfect. I'm sure there's something that'll do this for me, if anyone knows, thanks. Tested in UV with ZWB1/antilia u stack, worked great if I timed the flash right. Cut CD case as a cover Couldn't wait for my Dremel to charge, so pried that cover out. Only broke it a bit

Hello, fellow members. I come to your with a question that might belong here, it might not, I'm not sure. It's more of a need of advice rather than an exact question. I wanted to ask my parents if they could possibly get me one of the 45W UV flashlights for Christmas, I know I have the Nemo, but the idea having the 45W is still appealing, especially if I was to take it outside at night, it would make it easier to light paint the environment. I have found two links on AliExpress, both appear to be the same product, yet one is significantly cheaper, almost half the price. Expensive: https://www.aliexpress.com/item/1005002133384717.html?spm=a2g0s.8937460.0.0.141c2e0eHLzRwT Cheap: https://www.aliexpress.com/item/1005002597782695.html?spm=a2g0s.8937460.0.0.141c2e0eHLzRwT The cheap store also sells another one of those which appears to be the same, but at higher price. https://www.aliexpress.com/item/1005002609148394.html?spm=a2g0s.8937460.0.0.141c2e0eHLzRwT I contacted the seller and they told me that they were selling the same item at different prices because of and I quote directly "Different advertising locations". It becomes even stranger when you look on the rating of the stores, the more expensive store actually has a lower rating by a few percent. Is it possible that this is in fact the same product, just way cheaper from one seller due to various business factors? I don't fear much for the batteries that come with the flashlight, I own a quality charger as per Ulf's recommendation, so there's little chance of them malfunctioning. Do you guys think the cheaper deal is legitimate?