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In another topic I lately tried to improve an UV-torch marketed to have a 120W input, and failed due to the original electronics design. https://www.ultravioletphotography.com/content/index.php?/topic/5122-alonefire-h45-45w-dissection-and-analysis/page/2/ At the end I mentioned that I might do a major redesign adding proper constant current driver-circuits. I have now decided it is not at all worth the efforts and costs. I searched for suitable ICs to use and the only type I found also need a complete redesign of the metal board holding the LEDs. To make it work the LEDs the would have to be de-soldered and re-transplanted onto the new LED board. There would be a need for three DC-DC converter circuits that just might be fitted inside the torch too. The risks and total cost of such an adventure are way too high for a short period of almost constant intensity, before it would have to be automatically switched off to save the LEDs form dying. The drive power could never be much more than 20-30W, giving maximum 7 - 10 W optical power. I have to accept that the torch I bought is a real dud! I have another UV-illumination project that is more interesting to restart. It has been dormant a few years. It is based on a Copper based LED array that I already have. The array has 15 pcs of 10W 365nm LEDs mounted on a proper copper-based PCB. With proper cooling and constant current drivers it will be able to push out ca 50W OPTICAL power for a 150W input! I have already assembled the array, heatsink, fan and UV-pass filter holder: The heatsink and fan combination is suitable for cooling off the heat from the LEDs. There will be around 100W to take care of. The filter will be quite hot as the transmission of 2mm ZWB2 at 360-370nm is less than 100%. Just now I do not remember the exact numbers, but it is low enough to heat up the glass. I will do this project in two main steps. First the driving would come from a Lab power supply and I will focus on the mechanical and thermal design. That will be a nice flexible light source for indoors UVIVF. Later I might make this lamp portable, for outdoor usage, with some belt or shoulder-bag based battery + drive circuit. The weight of a driver circuit and batteries will be way too high to be comfortable being integrated together by the LED head with heatsink and fan. The driver will instead be connected to the LED Head with a flexible cable. The LED-head will be handled like an old fashioned search light. I think the battery packs and connection mechanics will be salvaged from some 18V hand tool system. There will be at least two battery packs driving the CC-conversion modules that will feed the LED-head cable.

Maybe I have to put a UVC warning here, I'm not sure. Powerful (and expensive) UVB and UVC flashlights, LED-based. I have no affiliation with the seller. https://www.engeniousdesigns.com/shop

I have no affiliation with any sellers or companies mentioned in this topic. I recently did some searches on LEDs, since technology improves as time passes, and there could be new LEDs that were unavailable before. About 365 nm LEDs, I posted a topic some years ago (time flies!), and I haven't done new searches on this. Maybe some LEDs with improved efficiency or radiant power are available. If you search for LEDs online, especially if you search for a wide variety of wavelengths and power LEDs, you will notice that LEDs with wavelengths ranging from 365 nm to about 1050 nm are easily available with input powers between 1 W and 100 W (sometimes even more). They all look the same, with 1 W LEDs commonly available as a single chip (sometimes on hexagonal star PCBs), 10 W ones being made of 9 chips, usually connected in a 3S3P configuration, and 100 W ones being made of 100 1 W chips connected in 10S10P. The fact they all look the same makes me wonder if there's some kind of standard manufacturers are following. LEDs in this wavelength range are the easiest to find, they are efficient, and they are available in a lot of wavelengths. Between about 365 nm and 425 nm (UV to violet), you can find them in 5 nm increments (365 nm, 370 nm, 375 nm, ect.). The hardest ones to find are in the cyan (~480 nm) and yellow-green (~560 nm) regions, but if you search long enough you will find them. I have them in 10 W power, I still need to mount them on a heatsink (remember, it's important for power LEDs to mount them on a heatsink, they will overheat otherwise). I have recently discovered this company, which seems to make LEDs with a very dense selection of wavelengths (every 10 nm in the UV and visible range): https://www.bing.com/ck/a?!&&p=fa0e995133e1d8fbJmltdHM9MTY5OTA1NjAwMCZpZ3VpZD0yZjFkYzQ3My0zZDI0LTZlMzUtMjJkNi1kNmEyM2M1MzZmOGUmaW5zaWQ9NTIyMQ&ptn=3&hsh=3&fclid=2f1dc473-3d24-6e35-22d6-d6a23c536f8e&psq=Lumixtar&u=a1aHR0cHM6Ly93d3cubHVtaXh0YXIuY29tL3Byb2R1Y3QtY2VudGVy&ntb=1 I don't know how one can buy those LEDs. They would be useful if one wants to make a righ resolution LED monochromator. LEDs outside the 365-1050 nm portion of the spectrum are available, but noticeably harder to find. They are typically more expensive, avaliable with input powers of at most a few watts, and they are much less efficient. You can find them on eBay, but you should look for specialised companies, such as Thorlabs, for a wider selection. In particular, the next LED wavelength you will easily find below 365 nm is 340 nm. Thorlabs sells one (link), and you can find them on eBay (link). The LEDs look similar, but have different specifications. Both have changed around the same time to a newer model, and they looked identical previously. The eBay one should be model CUN4GF1B, produced by Seoul Viosys. What I find very weird is that there's no mention I could find on this LED on Seoul Viosys' site. I don't know if Thorlabs' LED is produced by Seoul Viosys too, but there's no mention about this company I could find. Can someone explain this? Thorlabs' LED claims a typical power output of 69.2 mW, and a power input of 3940 mW, with an efficiency of 1.75%. From the datasheet of CUN4GF1B we have a typical input power of 1025 mW (4.1 V and 0.25 A), and a typical power output of 40 mW, for an efficiency of 3.9%. Also, CUN4GF1B's datasheet specifies a minimum, typical and maximum current rating. What does that mean? There's another notable 340 nm LED I found, this one: https://shop.boselec.com/products/340nm-uva-led-smd-packages-medium-power It has an input power of 1575 mW (4.5 V, 0.35 A), and an output power of 160 mW, which means a very high efficiency of 10.16%.

UV highlights often record non-linearly. I can take a shot and, upon review, the histogram might show exposure peaking near the middle. Add perhaps 1/3 to 2/3 steps more exposure and the histogram is close to or crashing into the right side. This is all done with EL-Nikkor closed down to the same aperture and camera on manual. Light appears the same. Is there something about UV light that causes this? Thanks, Doug A

We all know about the oldest brute force technique for getting somewhat pure UV output, an incandescent bulb made of woods glass. What baffles me is that no matter where I look, all the bulbs made this way are regular incandescent bulbs, I never see a bulb made this way that would have the smaller quartz bulb inside. This is sort of frustrating because I have a halogen spotlight which is very good for mimicking sunlight in my multispectral photos, even being good enough for UVA without significant leaks. While I do know that having such a bulb would not be good for any practical purposes, I'd still love to have one for collection reasons, they don't seem to exist though.

I've been enjoying occasional shooting of UV induced visible fluorescence (UVIVF) but have found difficulty in holding my Tank007 TK-566 UV torch in the effective angle. Also, I have wanted a bit more powerful torch. Luckily a net shop based in Akihabara, Tokyo, has started to handle UV LEDs. So, I got a 5W 365nm LED and the holder/reflector kit designed to fit the LED. The forward voltage of the LED is 4V (typ.) and I wanted to drive it using a 5V AC/DC adapter, and a 1 ohm resistor connected with the LED in series was necessary to drive it at 4W. Here are the parts I collected. Front row, left to right: 5W 365nm LED, retainer, reflector, thermal grease, 1 ohm resistor, a set of screws to fix the LED and the retainer. Second row, left to right: back plate for the case, aluminium die-cast case which is also expected to function as heat sink, SmallRig cold foot, DC adapter input jack. I bought the 1 ohm resistor that was rated at 5W which was overkill. A 3W one should be enough. I was thinking that a 5W one was necessary because the LED was rated 5W (stupid me!).

Hi all. I am trying to figure out the best lighting solution for UVIVF photography involving small reptiles. In my testing, I managed to capture some neat fluorescence in a chameleon illuminated using a Lightfe UV301D torch. This torch has a "black filter lens" but I have no idea what material it is and as you can see in the attached image there is plenty of blue so it probably isn't a very good filter. The picture was taken at ISO400, F20, and a 1 second shutter speed. Now 1 second is fine for a slow moving and relatively calm lizard like a chameleon but for other critters I am gonna have a tough time trying to make them sit still for a long exposure. I was thinking that a modified UV flash might be better because it might be able to "freeze" motion like a regular flash would? But I have no idea about the differences in exposure times between using a flash and using a torch. Secondly, would one fire of from a UV flash produce enough UV light? I am assuming a flash is more powerful than a torch. Would it be better to go for a modified flash, either premade like the Kolari Vision multispectral flash or DIY with a yongnuo or godox and some filters, or would it be better to get a powerful torch like a Convoy or Nemo with filters. There's also things like the Adaptalux UV but I don't know if those are powerful enough for animals bigger than insects. Any advice and recommendations would be appreciated. On an unrelated note, does anyone know if Uviroptics is still available as a source of filters? Their page is empty on ebay.

[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. Hello there. It's been a long time since I posted. Life got in the way. But this video just came in and it is honestly a little bit concerning. Brainiac75 tests the output of halogen lamps and finds out they emit a small amount of UVC. I have an unfiltered 125w spotlight that I have used a few times as a lightsource and I am wondering what the implications of this are.

What is the Good, the Bad & the Ugly of this light please ? After making my rig very sturdy & with 1.25um steps & getting suitable photos with a 60x objective, I have started getting deeper into Microscope Objective Macro Photography, now with a 100x magnification. All went OK, except the lighting for the 60x objective wasn't enough for the 100x objective. The problem is the working distance is now only 2mm, & it is hard to get a strong light in that gap. I found this LED down light to be suitable with some modifications. The LED COB in this one is 7mm square & rated at 50w equivalent. Many other specs are useful, like 12v AC/DC & either polarity in 12v DC. The Data Sheet.... https://www.ledvance.com.au/en/product-datasheet/6864/31735 The plastic lens pops out with a thin lever, revealing the 7mm Cob LED. I then added an aluminium heatsink with a 16mm tube 150mm long. I will make four of these to place close to the 100x objective.

Are there any Epi-Illumination systems that work with M42 x1mm pitch extension tubes please ?

Adaptalux is offering a new unit on Kickstarter. It uses the same lighting arms as their studio unit. One of the packages has 365nm UV arms for UVIVF. I love my Nemo lights, but the Adaptalux would be so much easier to position. I'll probably pledge for a set. 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. UVIVF, UltraViolet Induced Visible Fluorescence, with many UVA, UVB, UVC, LED lights & Far UVC Excimer lights. I now have a collection of UV LED lights, 365nm, 340nm, 310nm, 395nm, 375nm, 365nm, 255nm & 222nm Excimer Far UVC lights. I have been developing my Macro set-up & light stands. These are taken with an unconverted Sigma fp camera with a Sigma 70mm macro lens. The rock/mineral sample is one in my collection from the Puttapa Zinc Mine, South Australia, & contains willemite, calcite & smithsonite, plus others. I have tried to process these all in a simple & similar way. I have adjusted the shutter speed & aperture to maximise the dynamic range in the histogram to fill it from left to right. Processing has been minimal to white balance on the black cap the rock is sitting on & sharpened in Topaz Sharpen AI. First in Visible Light 400nm - 700nm. Far UVC 222nm Excimer Light, Induced Visible Fluorescence, safer to use. Protect eyes, face & all skin. UVC 255nm LED, Induced Visible Fluorescence, knowledge of the safe handling this light is needed. Protect eyes, face & all skin. UVC 265nm LED, Induced Visible Fluorescence, knowledge of the safe handling this light is needed. Protect eyes, face & all skin. UVC 275nm LED, Induced Visible Fluorescence, knowledge of the safe handling this light is needed. Protect eyes, face & all skin. UVB 295nm LED, Induced Visible Fluorescence, knowledge of the safe handling this light is needed. Protect eyes, face & all skin. UVB 310nm LED, Induced Visible Fluorescence, knowledge of the safe handling this light is needed. Protect eyes, face & all skin. UVA 340nm LED, Induced Visible Fluorescence, knowledge of the safe handling this light is needed. UVA 365nm LED, Induced Visible Fluorescence, knowledge of the safe handling this light is needed.

[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 want to buy a powerful low pressure mercury lamp that I can use from wall socket (220V) - ideally E26/E27 but can be something else if I can adapt it to wall socket. I already have 3 bulbs E27 rated 25W. I've found some more powerful but delivery time is 40+ days and source is China. Does anybody know any particular model name/brand name so I can look directly for it? I want it tyo produce as much as possible 253.7nm and 184.45nm (I want lamps that do not block this ozone genrating frequency). Ideally they should be up to 1 kW. Would be really if anybody can provide any search hints... I DONiT want LEDs - they are only 1% efficient, this must be mercury low pressure lamps, I can consider high pressure lamps but then filtering out other frequencies becoming extremely difficult while most of them also block UV-C which is the opposite of what I want... [UV-C is dangerous]

In my efforts to get to the first base of UV photography, I brought a few Vivitar 285's and started converting them according to guidance here etc - including precautions for risk from the dangerous high voltage circuitry. So far I'm not too unhappy - two successfully 'converted'; one more dead (seems to have been a late model with incredible fragile soldering; now charges but won't discharge). I noticed, however, that the UV output of when using one flash is quite low and the unit has to be very close to the subject at full power to get half-decent exposure. This is limiting my aperture and sensor ISO choices. Ideally, I'd like to use the same flash position for visible and UV with the same camera setting (just changing the filters) but I can't reduce the output enough (min 1/16) for visible light so I'm having to use a second unconverted flash further back for visible comparison. For the conversion, I've used a replacement window over the flash tube and reflector made from CD case plastic. I think this is likely to be a polystyrene-type material. It does appear to transmit a good amount of UV at 365nm based on a crude torch test (with and without subject material, UV torch and visible fluorescence of 'white' items with optical brighteners). So, is the low output due to a coated flash tube, inherently low UV output, absorption by the CD material, or absorption by the zoom head fresnel (OK with UV torch) Would using UV transmitting acrylic, UV glass, or fused silica (quartz) likely work better? I'm guessing no window is not recommended? In addition, is there any info on how far into UV I can expect these units go? It seems to depend on the grade of quartz used to form the tube but I don't seem anything specific to these. For fluorescence work, I presume that windows made from ZWB2 would suffice? Seems like a lot of questions; any advice gratefully received!

Hi, simple quick question: Is it possible to convert Nikon SB800 flash to full-spectrum If so has anybody ever tried and can provide a spectrum of such converted flash? Or maybe just an approx range of wavelengts like from about 300nm to 1100nm? Does it reach UV-B - like down to 300nm? (not even speaking about UV-C)

I see that it is impossible to find something that I want to buy (excluding aliexpress but they always have exactly what you need and cheap, the problem is that I don't believe them at all). I'm also not a tech guy so I cannot do this myself, but I;m wondering if there is any company or individual that can create a flashlight for me. I would like to install array of 16 UV-C diodes (4x4) in some already existing flashlight just to have an shortwave UV flashlight (this includes all additional details like aluminium reflector, quartz lens/glass and power supply). Any ideas where can I start searching for somebody who can custom make such a thing? Or maybe somebody from this forum can do this and want to earn money? I'm considering 255/265/275 up to 310 nm LEDs - I would just pickup ones that have most UV output power (not input power) and ieally below 280 nm (310 is probably a separate story), for anything above 320-330 nm I already have my greatest firend - sun - I need nothing more.

Some time in the future I would like to try UVIVF with my Godox AD200 flashes. The Speedlite-head H200 that comes with the flash is very fast and easy to modify. You just need a PH1 screwdriver to loosen two screws to reach and replace the thick inner glass filter while at the same time remove the fresnel lens. Retightening the screws need some finesse as they are screws cutting their thread into a hole in the plastic structure. The H200 heads can be bought separately if needed. I discussed with my optician, the possibility to shape a filter glass after the shape of the original glass filter. He wanted to try doing it with his advanced grinding machine. Last summer I bought a few ZWB1, 3mm with a diameter slightly bigger than the original filter. At the same time I also got a few FS windows, 2mm with the same diameter. Yesterday I finally got the filters reshaped. They fit perfectly into the gasket and slot in the flash head. The modification took less that a minute per flash head. From left to right, bottom row, shaped ZWB1, fused silica window and original yellow-tined glass filter. Top row, two flash heads modified with the filters. The rightmost head, unmodified and with the fresnel lens in place. The flash tubes in these flash heads are uncoated and emit a nice amount of UV. Here is a link to a post with pictures showing the flash head separated and also some emission graphs: https://www.ultravioletphotography.com/content/index.php?/topic/3206-is-the-godox-ad200-ttl-pocket-flash-kit-uv-convertable/#elControls_26649_menu

Hi I have a question (maybe somebody is familiar with those) - https://www.ebay.com/itm/323610114425?mkevt=1&mkpid=0&emsid=e11051.m43.l1123&mkcid=7&ch=osgood&euid=e51af7b736b44a8c8bcf0a1966edd8d7&bu=44153275185&osub=-1~1&crd=20220812234110&segname=11051 - https://www.ebay.com/itm/224709443275?_trkparms=amclksrc%3DITM%26aid%3D1110002%26algo%3DSPLICE.SOI%26ao%3D1%26asc%3D20201210111451%26meid%3D8b1b5fee888448faaf56e2d951e2cf00%26pid%3D101196%26rk%3D1%26rkt%3D12%26sd%3D323610114425%26itm%3D224709443275%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DPromotedSellersOtherItemsV2WithMLRv3&_trksid=p2047675.c101196.m2219&amdata=cksum%3A2247094432758b1b5fee888448faaf56e2d951e2cf00|enc%3AAQAHAAABALB59iZaq6L1SxCGLGoiBqHdpPz8nqKyKuGL1QIa0H%2B4RjlnzY44V7F4peTZsE%2B8I8pVRzfWAREG5qYey5oz%2BjhItNBwxlQNCek29dPHBA1eVYkPVjmL%2FMxxtG98Rt3pIVNGTV4DRD7X28R1jDYbW83runSFuBG58JMnrtHKq802wyB%2BZEkWcW6X7RhVZOuLXXbyskFHWGkkxZXoCzV7S6gRbUE1mQkc87NRmSmH2dMYCm7ZgdFyBV%2BbMt%2BE2tKo%2BDg1Z96EU3ORMSBgsNkSjnnmHd%2FknfuG52CfW1y69NGerRuXwNtScNVIYQ4n%2BE1dHv3X0DycQs1ZC%2F3MUoUvTNQ%3D|ampid%3APL_CLK|clp%3A2047675 Are those watts 1.7W, 7.2W values for UV-B output? I've asked the seller and he answered that yes, but I wonder if this is true or not... 7.2W of UV-B seems quite interesting for $60, will it be usable for iluminating targets for photos? Does it make any sense to consider them as UV-B lighting?

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

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.

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.

[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 ?