Macro under UV light

Looking to see if there is any experience that I can learn or steal from here. I have just bought a really cute 395 nm UV LED which I want to use for insect photography (as well as mineral and plant subjects). Before I start wasting a lot of time on understanding exposure algorithms, has anyone here done anything similar? In particular, what are the rules for setting exposure? I have not yet even taken a first test exposure, so all responses are welcome.

Thanks

I've done this, but on a different scale using a broncolour UV modifier.

Your not actually photographing UV light, it's largely invisible to the camera and entirely invisible to us, and beyond the ability to be viewed in a digital system.
What you are photographing is florescence: https://en.wikipedia.o​rg/wiki/Fluorescence

This makes it really tricky to find the correct exposure, a good reflective light meter might work, but the easiest way to do is just trial and error, watch the histogram and find an exposure that you like and that works for the subject.

Sounds like it could be a very interesting area, taking macro pics with actual UV light. But a cursory check on Google suggests you would need to get some appropriate gear, including a camera with any UV-obstructing filter removed from the sensor, a lens that can pass the UV wavelengths you are interested in, a filter to block visible light, and suitable UV light sources.

ECC233 wrote in post #18824877
Looking to see if there is any experience that I can learn or steal from here. I have just bought a really cute 395 nm UV LED which I want to use for insect photography (as well as mineral and plant subjects). Before I start wasting a lot of time on understanding exposure algorithms, has anyone here done anything similar? In particular, what are the rules for setting exposure? I have not yet even taken a first test exposure, so all responses are welcome.

Thanks

Like mentioned above, you are still (mostly) imaging visible light. As the camera's exposure meter doesn't know if the light is being reflected or emitted by the object, it may still work and provide a usable exposure. I currently image TLC (thin layer chromatography) plates illuminated at 254 nm, with a Canon 6D and I only use the camera's exposure meter with good results. If I remember, I'll post some images tomorrow. That camera works well enough they I only hand-hold the camera. I use 2 lamps to evenly illuminate the plate since the inverse-square law still holds, and the brightness drops off due to distance and how the light spreads from the lamps. These images are used to document various experiments. I also image fluorescent fractions at 395 nm- I use these images to document instrument tests. I'll try to remember to post some of those, too. Again, the exposure meter does a good job for me. The lamp is very close to my experiment in these cases. If you move the lamp away from your object, you may need to use a tripod, and if the fluorescence gets dim, you may need to manually set the exposure,

The light you are using, 395 nm, is just outside the visible range. The lamp doesn't emits a single wavelength, but rather a range of wavelengths- you'll see a purple color from your lamp for that reason, and depending on lamp placement, you'll image that light as well.

I respectfully disagree that UV light is "beyond the ability to be viewed by a digital system" as I used to do it in an earlier job. You can have the "hot mirror" replaced in the camera with a UV band-pass filter- the sensor is unchanged: https://www.lifepixel.​com …dslr-uv-camera-conversion
The lenses we use can also focus UV light, although some are better than others: https://www.lifepixel.​com …-uv-camera-considerations. Some people image in UV with just a filter, and take a long exposure on a tripod. They sell filters for microscope imaging for fluorescence, which emits in UV: https://www.semrock.co​m …escence-applications.aspx the cameras used here are different than the ones we use, but the sensors are often the same.

Back to your question- Tonic water fluoresces nicely when excited by 395 nm light (quinine) and can look like it is radioactive.
Here's a list of fluorescent things- you have a long wave UV lamp: https://aiccm.org.au …als-relevant-conservation
Scorpions fluoresce (https://www.sciencedir​ect.com …cle/pii/S000334​7211005069 ), and flying squirrels were recently reported to have a pink glow: https://www.sciencedai​ly.com …/2019/02/190205​102612.htm . Scientists have genetically engineered fish to fluoresce (not to be confused with the fluorescence technique FISH ): https://www.glofish.co​m/
These fish were originally intended for research.

Thanks both. I should have been a bit clearer. I meant it in the capn Jack sense of taking images of the luminescence. I will use a UV-A filter to protect the sensor (probably unnecessary). As soon as I have anything I‘ll post some images/links.

Here are some shots of fluorescent things- these are quinine (compound in tonic water). Note that the camera is looking at the lamp, with the purple color I mentioned earlier. I use no filter or other protection for the camera.

Here are a pair of TLC (thin layer chromatography) plates. They are silica, with zinc silicate (F254 indicator). This absorbs 254 nm light and emits in the green range. The compound being run on the plate also absorbs light, but doesn't usually emit any light. Since it absorbs light, the underlying indicator has less light, with less fluorescence, causing the dark spots. Two lights were used.

Funnily enough I tried a couple of tic plates myself in the lab today.

First attempts with a fluorspar crystal. I think I need a 400 nm shortpass filter to get rid of the blue radiation from the LED