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Hello. Long time no post for me. I decided to get my flash units out for a play. Making the video was a learning curve, Davinci resolve is a complex program and I am yet to learn a lot so please dont knock my editing skills.

Editor's Note: I split off StephanN's high speed UVF work from Adrian's topic where it was originally posted. The previous link was UVF high speed - just for fun I've also tried my hand at this sort of sculptures, though not aiming at recreating the milk-image. Of course, having done quite a bit of photos with ordinary drop-photos did help (http://www.photo-cha...ategory=tropfen ) My setup is a Canon 5DSR with Tamron Macro 180 f/3.5, UV-flash from Helling (apparently a modified Yongnuo-flash), camera and valves triggered with the famous GlimpseCatcher, flashes triggered from on-camera remote trigger. The fluorescent dye was bought on Amazon, I think. I didn't have any problems with blurred sculptures, as long as I had the flash below roughly 1/4 of maximum power. However, I did increase the power deliberately for some "action"-shots.

I went back to the Community Garden at midnight armed with my Sony A7S conversion, the Sony FE 1.4/24 GM lens, and a Hoya 25A filter (long pass starting around 600nm - a red filter) and my Nemo torch for some UV-induced infrared fluorescence (UVIIF). Sunflower with a sleepy pollinator (all these photos have been white balanced to remove the strong color cast, and street light IR has been subtracted off) 1-1 crop Assorted flowers and a stripped insect

Simple question, I didn't do any fluorescence photos yet and I'm just wondering about wavelenghts - Assume I have 222nm UV light source, what kind of fluorescence can it create? Is there any rule about what wavelenghts cause what other wavelengths fluorescence? I saw example of UV causing VIS Fluorescence and VIS causing IR, so I see shorter wave cause longer wave fluorescence, but how much longer - is there any limit? Say can 222nm (UV-C) cause 888nm (IR) F (4x longer wave)? Or maybe up to twice length or any other rule?

This is probably more violet than it should be because I accidentally left my Tiffen Haze 2E at home, but it still looks pretty. [*] https://www.youtube.com/watch?v=SLCuL-K39eQ

It was a white orchid. Tiffen Haze 2E filter on the unconverted Sony A7III, 365nm Nemo torch, and white balanced to taste. The tiny amount of ambient light remaining has been subtracted off. This is now my standard procedure to ensure I'm only seeing the fluorescence. It's extremely easy to do, so I recommend it to all. You just shoot an extra photo with no torch and then use Difference on the top layer in Photoshop (or equivalent in other programs).

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

A wind storm knocked this limb to the ground. Found it while walking with the Nemo torch and brought it inside. This time I tried the Pentax D FA 645 55mm lens with extension tubes on the Pentax 645Z. Mounted the Tiffen UV 2A on the lens to block all UV. I used the standard Nemo filter and added the Schott S8612 for IR blocking. ISO 200 at 30 seconds F22. This macro is about lifesize magnification. I wore the Honeywell yellow goggles for safety. Was motivated to go out walking with the Nemo by @Fandyus and @Andy Perrin. Lots of fluorescence in the woods. The colors do seem purer, this time, with the S8612. Thanks for looking, Doug A

I wonder if anyone might have any ideas on this please? I have been shooting some short duration flash images for a new book, of tonic water being poured into a glass. Every image has a red catchlight, whatever the position of the flashes, even those shot without the pouring. Technical details: 2 x Metz 45CT1 flash guns with UV absorbing window removed, and replaced with one half of an old Kodak 18A "Wood's Glass" filter (I have checked, this is light tight) Camera: Nikon D800 with 105mm micro-Nikkor. 1/160th @ f/11. Flash duration approx. 1/2,000th second. Thanks for looking!

I am puzzled. I have been scratching my head for ages trying to work out why UV photographs taken with the full-spectrum-converted Olympus E-M1 (Mk1) camera I have been using for some years show diffuse yellow halos around strong highlights... The answer I seem to have found... seemed illogical at first, but I am now quite convinced the camera sensor itself fluoresces. It fluoresces enough to be visible to the eye. Has anybody seen something like this before? It seems to be the sensor itself that fluoresces, but it could also be related to the "proprietary coated glass" used as filter replacement by DSLR AstroTEC (http://www.dslr-astr.../index-eng.html) for the conversion. Fluorescent coatings are used on some sensor arrays of spectrometers to extend the sensitivity deeper into the UV, but this makes little sense for a normal photographic camera. What is the evidence: 1) For some time I have noticed that the yellow halos did not differ much in sunlight, using a "full-spectrum" flash or using a 365 nm flashlight. 2) I started suspecting that the cause could be fluorescence of the lens itself as I was using front mounted filters (both Baader U, and StraightEdgeU. 3) I could still see the halos with SWB1 and SWB2 3mm filters mounted behind the lens in a DEO-Tech OWL adapter with a filter drawer. 4) Yesterday I slightly "shortened" a spare Baader filter ring, so that the Baader filter would easily fit in the OWL adapter, the halos were still there. 5) I went into a darkroom shined my 365 nm LED "flood" flashlight into the camera, and the sensor glowed rather faintly clearly yellow. 6) Today I took photographs of the glowing sensor (of course also showing the blue fluorescence from dust and lint). Both photographs were taken with an off-the-shelf E-M1 mk II, with a M.Zuiko 60 mm f:2.8 macro with a Zeiss T* UV filter stacked with Tiffen Haze 2A filter. In addition to the fluorescence of the sensor, the strongly fluorescent red index dot can be seen. The badly done reassembly and chipped glass edges can be also seen. The M.Zuiko 60 mm f:2.8 transmits very little UV radiation itself.

Some more UVIVF with subtracted ambient lighting. Procedure and equipment was identical to what I used for the flower in the last post.

I'm using the Tiffen UV haze 2A that cuts off at about 410nm. The 2E cuts off at about 385. Would the 2E improve results shooting UVIVF with the Nemo 365 torch and a stock camera? On daylight preset my images are slightly bluish with the 2A. Would the 2E reduce this? Wouldn't it make even more difference with electronic flash? Thanks, Doug A

Amazing results. How is he doing it? Extremely long time exposures? https://www.thisiscolossal.com/2022/08/cody-cobb-spectral-photos/ Thanks, Doug A

Here are two pitchers from the same Sarracenia carnivorous plant (Sarracenia sp.), photographed in UVF. The pitchers are different ages, i.e. a relatively young one and a mature one. They give a completely different appearance in UVF. I think the older pitcher is exuding more of the liquid sap which attracts insects to it. The plant itself is quite large with a range of different aged pitchers so I will try some more images with more pitchers. Technical: Nikon D850 with 105mm micro Nikkor. NEMO torch, light painted 20 seconds at f/16.

This was without the image subtractions (it wasn't necessary in the very dark woods), so just light painting. Saturation has been increased for the sake of art. Camera: Sony A7III unconverted Lens: Sony GMaster FE 24mm/1.4 Torch: Nemo, with the filter it came with Filter on camera: Tiffen Haze 2E

Continuing with the work I did awhile back with the Queen Anne's Lace and the tree stump, I did a flower photo, UVIVF, by image subtractions to remove the street lights. Camera: Sony A7III unconverted Lens: Sony GMaster FE 24mm/1.4 Torch: Nemo, with the filter it came with Filter on camera: Tiffen Haze 2E The final image: The image with fluorescence + streetlights (contrast is deliberately low here to keep pixels from saturating): The image with just streetlights:

Here's some light-painting for you all. These are panos taken with a Sony Zeiss FE 55mm/1.8 lens. WB significantly altered all over the place, and I brightened shadows etc. to taste. F/1.8 (a poor choice, but the high resolution made up for the bad depth of field), ISO100, 10" F/8 (I realized the error...), ISO1600, 30" And not related to UVIVF at all, here is just a nice pano of the lovely mirror reflection on the pond. Crop:

This is the edge of Chandler Pond in Boston, illuminated by a Nemo torch, captured with an A7III (unconverted) with a Tiffen Haze 2E filter (420nm cutoff) and EL-Nikkor 80mm lens. I focused by live view. Minimal natural light was present, since I was deep in the weeds. Exposure is unknown, since I couldn't read the F-number in the dark! But it was ISO6400 30sec. Daylight WB was used and not altered. Topaz sharpening and denoising were applied. Other than that just normal contrast adjustments. The shadows caused by the floating weeds give it an interesting 3D appearance.

So today we went to a huge asian run store which carries all sorts of exotic food. They had a whole isle dedicated to just different kinds of soy sauces, fish sauces, rice vinegar, rice wine and other. But that's besides the point. I got me some healthy sesame oil but I got something for my pet rats as well. One of those things was a bucket of dehydrated silkworms to give as treats. I decided to shine my UV flashlight on it (as I do with every new object in my room at this point) and it looked really interesting. Take a look yourself. There ended up being quite a lot of variation between specimens, I just hand picked a few different ones. As you can see, some were entirely bright, some mostly dark, and some dark with spots. I broke one of the worms apart and it turns out that the matter inside fluoresces the same way as the bright spots. That makes me think that the bright spots are places where the worm was injured prior to being dried out, which is rather grim.

Pool of water in front of my outhouse during spring melt in early May while still somewhat dark in the night, first Visual, partly lighted by warm light from inside my cabin: Then UVIVF painted by Convoy S2+ 365nm and Tank 007TK-566, both with what is likely ZBW2 filters on the front. Since these were captured with my 12-24mm f/4 (on D500 @ f/9, ca 30 sec exposures) , I had no UV filter for the lens. Another smaller meltwater pool, similar equipment, 15 sec exposure We had a previous thread on this fluorescence a previous year, then while the water was frozen at the surface: https://www.ultravioletphotography.com/content/index.php?/topic/2713-frozen-outdoor/ I think the conclusion was that the fluorescence is caused by cyanobacteria, or perhaps just organic matter in the meltwater.

Saw this from Edmund in my email today: https://www.edmundoptics.com/knowledge-center/trending-in-optics/ultraviolet-lasers/?utm_medium=email&utm_source=application&utm_campaign=master_optics_at_home_content&utm_content=ultraviolet_lasers_tio&utm_term=laser_applications&mkt_tok=OTUxLVdYVy04NDQAAAGE7RvaqULWKUw81mpP9s7C28-AijWaJkluBh8xVT_Xyx750bHKBMofQtLX3IPyhgGpJVM4JcynVcbBrgOF3FiQNChx3yJlhHYX5O-k10wz0B7LSA 261nm is a bit on the short side, but imagine the fluorescence! I’ve done some Laser Induced Fluorescence (LIF) experiments on here with 405nm lasers.

I'm curious as to whether or not a pollinator would "see" UVIVF during the day. I did find one paper in Nature showing that pollinators respond to blue UVIVF in grasses [LINK] but not sure if a bee would "see" solar UVIVF. In Beebalm, the really bright spots are where the flowers bud out.

UV A,B,C, Excited Fluorescence of Some Random Minerals. Various UV lights from 222nm to 365nm to excited some random gravel size minerals. The lights are UV LEDs of various UV wavelengths from 255nm to 365nm. Most of the LED lights are about 9 watts, the 365nm is 14 watts. There are two UVC tube lights as well, 60 watt 222nm Excimer tube & a 40 watt UVC Compact Fluorescent tube. All the UV lights are filtered to not show any visible light. This is just a comparison of the fluorescence that these minerals show when excited with different wavelengths of UV, A, B, C. I may repeat this exercise again with a bit more preparation ? I probably will do this again, but with single pieces of identifiable minerals & to avoid the extreme dynamic range of the mixed minerals. I have some higher watt LEDs of some of these wavelengths, which I will use. Visible Light of Some Random Minerals. 365nm LED Excited Fluorescence of Some Random Minerals. 340nm LED Excited Fluorescence of Some Random Minerals. 310nm LED Excited Fluorescence of Some Random Minerals. 295nm LED Excited Fluorescence of Some Random Minerals. 275nm LED Excited Fluorescence of Some Random Minerals. 265nm LED Excited Fluorescence of Some Random Minerals. 255nm LED Excited Fluorescence of Some Random Minerals. UVC CFL Excited Fluorescence of Some Random Minerals. 222nm Excimer Tube Excited Fluorescence of Some Random Minerals. Visible Light of Some Random Minerals.

Recently, I had the good fortune of photographing a dragon fruit flower (Selenicereus undatus). The flowers of this plant are nocturnal an last for only one night. A full spectrum modified Canon 6D with a Sigma 105mm f/2.8 EX DG Macro Lens was used. Light sources: 365nm Alonefire H42 + 365nm Topcom 18w UV torches with stock front filters 395nm Uranusfire T6 + 395nm Topcom 18w UV torches with ZB2 (similar to BG3) filters LetonPower BB27-1S 27 LED underwater torch with red and blue (450nm) led lights Visible light (with clip in Astronomik 'L' UV/IR cut filter) UV 365nm light with ZWB1 (2mm, similar to UG11) + QB21 (2mm, similar to BG38) filters stacked on lens UVIVF 365nm with Tiffen Haze 2E filter on lens + clip in Astronomik 'L' UV/IR cut filter UVIVF 395nm with Hoya X0 filter on lens + clip in Astronomik 'L' UV/IR cut filter Infrared under white light from LetonPower BB27-1S with Astronomik 642nm clip in IR filter Infrared under 450nm blue light from LetonPower BB27-1S with Astronomik 642nm clip in IR filter Infrared under 395nm UV light with Astronomik 642nm clip in IR filter Regards, Troy C

There is no escape. Eventually we all are going to get it. Ruth and I have kept Covid-19 away for > 2 years. Until this morning, that is. While waiting for the second test to go positive, I can investigate how the motif looks in UVIVF. As I suspected, not very interesting or enjoyable. Just like everything else these war-ridden times.