Hello

[Rhabdophane]

Hi,

 

Name's Tom, from the UK. I work in the contaminated land sector and for a recent project we were interested in doing some UV fluorescence photography. Certain types of contamination will fluoresce under 254 nm UV light so we wanted to get a visual distribution of pollution. We managed to cobble something together but it wasn't a very refined setup, so I've joined here to try and learn a bit more and see how we can improve things for future projects.

 

I also enjoy photography as a hobby so am quite interested in learning a bit more about UV photography in general.

 

Anyway, I'll have a poke around the forum and will get around to posting some more technical questions at some point.

[colinbm]

WARNING UV light is dangerous to living tissue including you !

 

UV excited visible fluorescence photography is relatively easy. you just need an off the shelf digital camera & a Zeiss T* UV blocking filter.
https://www.zeiss.com/content/dam/consumer-products/downloads/photography/datasheets/en/filter/datasheet-zeiss-uv-filter-en.pdf

UV comes in different wavelengths from say 200nm to 400nm, aka UVC 200nm - 280nm, UVB 280nm - 315nm, UVA 315nm - 400nm.
I don't know what the material is that you are looking for, but some materials react best to one or more of these bands of UV A, B or C.
Having UV lights of different bands will help you decide which are best.

Color Gems in the Netherlands has a great & powerful range of hand held UV torches & larger lights for searching over a larger area.
https://www.colorgems.nl/
The web pages are in dual languages, Dutch & English.

[Andy Perrin]

Yeah, make sure you are wearing sunscreen or skin coverings and eye protection when you work with UV-C. I have a friend who gave himself a nasty case of UV-C photokeratitis by accidentally flashing himself with a UV-C lamp meant for sterilization. That was literally last week. As the number of UV-C sources grows in our daily lives, I'm sure we'll see more and more of these injuries. My friend's eyes are recovered now but for whatever unknown long-term damage results.

[Andrea B.]

Scary story, Andy. Happy to hear this person is OK now.

 

Rhabdophone, welcome. I hope we can help. 

PLEASE READ THIS: [UV SAFETY] UV-C Light Is Dangerous

 

Also, for capturing UV induced fluorescence, the use of proper filtration on both the light source and the camera lens is mandatory. We have a brief write-up here about Visible fluorescence: LINK

 

[Doug A]

Welcome Rhabdophane. What an amazing project. Are you photographing small, macro size areas or large pieces of land in one image? Please be careful.

Thanks,

Doug A

[Rhabdophane]

Thank you for the links, Andrea - very useful resources.

 

On 3/13/2024 at 5:13 AM, Doug A said:

Welcome Rhabdophane. What an amazing project. Are you photographing small, macro size areas or large pieces of land in one image? Please be careful.

Thanks,

Doug A

The samples we're looking at are ~1 m long cores. So that was part of the issue we had - we have a handheld light similar to the ones on the site Colin posted, but that can only illuminate an area of ~10 cm... so what I ended up doing was taking a series of photos and stitching them together.

 

We bought a medical sterilising unit with 1 m long 254 nm UV-C light but the visible light it gave off was too bright so it definitely looks like not having the right filter on the light source was the main issue we had. Example photos attached - didn't actually see much contamination in these samples but get some nice orange fluorescence (probably a mineral like calcite) in the sample illuminated by the handheld light, but just a blue glow in the sample illuminated by the sterilising unit. So yeah, looks like getting a properly filtered UV light would be the priority for the next time I do this.

 

Agreed about the health and safety - we had a blackout curtain over the the door and I was operating the camera remotely through an app. Plus eye protection whenever I was in the room with the light.

 

 

 

[colinbm]

Could you tell us the material you are specifically looking for please ?

[Doug A]

20 hours ago, Rhabdophane said:

Thank you for the links, Andrea - very useful resources.

 

The samples we're looking at are ~1 m long cores. So that was part of the issue we had - we have a handheld light similar to the ones on the site Colin posted, but that can only illuminate an area of ~10 cm... so what I ended up doing was taking a series of photos and stitching them together.

 

We bought a medical sterilising unit with 1 m long 254 nm UV-C light but the visible light it gave off was too bright so it definitely looks like not having the right filter on the light source was the main issue we had. Example photos attached - didn't actually see much contamination in these samples but get some nice orange fluorescence (probably a mineral like calcite) in the sample illuminated by the handheld light, but just a blue glow in the sample illuminated by the sterilising unit. So yeah, looks like getting a properly filtered UV light would be the priority for the next time I do this.

 

Agreed about the health and safety - we had a blackout curtain over the the door and I was operating the camera remotely through an app. Plus eye protection whenever I was in the room with the light.

 

 

 

Thanks for the explanation and images. I've never worked with UV-C, but don't remember anyone ever having too much UV light. You are likely correct about needing different filtration. 

Good luck,

Doug A

[Rhabdophane]

On 3/17/2024 at 10:06 AM, colinbm said:

Could you tell us the material you are specifically looking for please ?

We're looking for non-aqueous phase liquids (see here) - petroleum products, essentially.