Make It Glow: a Flash Upgrade to Ultraviolet

I needed an outlet for my build-brain (yes, it's a thing, I don't have to explain that here, do I?). I have always wanted to try UltraViolet Induced Visible Fluorescence (UVIVF) Photography, but I could never quite find the time or energy for it. After leaving a time-consuming research job, I finally had the time to explore, experiment, and play with light. So I decided to upgrade a flash.

This project was the perfect start to a series of one-day-builds as it was quick; I had all the parts I needed; it has been on the list for too long; and most importantly, I get to play with a different kind of light.

Perhaps it's my research and microscopy background, but my photography is not a means of artistic expression, it is a tool for exploration. A way to study or understand something new. A way to see the unseen.

Ok, let me be honest with you, this was 30ish% me just wanting to make stuff glow and 5% wanting to tell my nephew that I was working with invisible (UV) light. What can I say, I'm a big kid, I love glow in the dark stuff.

If you want a mini physics refresher, I will list fundamental concepts at the end. This information isn't necessary to upgrade the flash, but its always nice to understand how things work.

Ok, let's get to work.

W A R N I N G

The capacitor in a flash can cause serious injury or death!

If you do not know how to work safely with capacitors, STOP! Take your flash to a camera repair shop. Ask to have the plastic diffusers removed. Then come back and skip to step 5 & Install the Step-Ring/Filter Holder.

EYE SAFETY

UV light can cause ultraviolet keratitis (snow blindness/welder’s eye) macular degeneration, cataracts and cancer.

Always wear the appropriate safety glasses when working with UV lights. Look for safety glasses listed as Ultraviolet Radiation Blocking Spectacles/Glasses/Googles

UV capable Flash

52mm UV Bandpass filter

52mm IR Blocking filter

77-52mm Step Up Ring

Screwdriver (Flat and Philips head)

Black Tape

UV Safety Glasses

Why these items where used:
A Godox TT600 flash was used for the most basic of reasons…I had one. So, it got a considerable upgrade from plain ‘ol boring visible light to UV, and I couldn’t be happier with it. I mean, who doesn’t like glow in the dark stuff!

I used a 52-77 mm Step-Up Ring for a few reasons:

• I could only find 52mm filters
• I needed a way to attach 52mm filters to a 77mm-long flash head
• I had a 52-77mm Step-Up Ring :)

I was out of gaff tape. What can I say, it happens.

• Place the flash on its side
• Use a small flat-head screwdriver to pop off the rubber covers
• Use a small Phillips head screwdriver to remove 2 of the 3 screws (see image)
• Flip the flash over and remove the rubber cover and 2 screws on the opposite side
  • Note that the rubber covers are not interchangeable. They are indexed for each side and labeled "R" and "L"

• Use a Phillips head screwdriver to remove the two screws securing the cover plate
• Remove the cover plate
• Take note of the orientation and stacking order of the plastic diffusers
  • This is just in case you want to revert the conversion

• Slide the clear plastic panels out
  • These block UV light

• Reinstall the cover plate and secure with its 2 screws
• Reinstall the 2 screws and rubber cover on each side of the flash

Use tape to secure the Step Ring to the front of the flash head.

Learn from my mistake and use gaff tape. It will be easier to adjust if you do not align it perfectly on the first try. It will also be easier to remove if you want to revert the conversion.

• Install the step ring with the 77mm side facing the flash. It will fit snugly around the flash head
• Use a 2 inch piece of tape to secure the step ring to the side of the flash head
• Flip the flash over and add a second piece of 2 inch tape to secure the step ring to the flash head

Preventing light leaks is as important as wearing safety glasses.

• Carefully wrap a strip of tape all the way around the step ring and flash head
  • Take care to line-up the tape with the step ring's edge
• Once you are happy with the alignment, press the tape down onto the flash head
  • This will both, secure the step ring to the flash, and keep light from leaking
• Add a second layer if you have any gaps in the tape

Simply thread the filter onto the step ring

• Install the IR blocking filter
• Install the U-340 filter

Put on UV safety glasses before powering up your flash

Test your new UV flash out on some flowers or other household items.

• The electromagnetic spectrum is a range of wavelengths of electromagnetic radiation. Simply stated, It's all kinds of light: Gamma, X-ray, UV, Visible, Infrared, Microwave, and Radio.
• For this discussion, we only care about Visible, Ultraviolet, and Infrared (IR).
• The human eye cannot see most of the electromagnetic spectrum, only a small range.
• Visible light has wavelengths between ~400 to ~700 nm.
  • As the name suggests, it is what we can see.
• UV is below 400 nm.
• Infrared is above 700 nm.
  • This is something most camera sensors can detect, at least in the low range.
  • For "normal" photography, visible light drowns out the IR, so we don't worry about it.
  • In UVIVF photography, there is little to no visible light, so the small amount of IR light contaminates our final image.
• For UVIVF, we only want UV light from the flash.
  • Flash tubes (the bulbs) are capable of emitting UV, visible & IR so we need to filter out a lot of light.
  • A UV bandpass filter allows UV light to pass while blocking visible light.
    • These filters usually leak a little IR.
  • An IR cut filter blocks IR.
  • If we stack a UV bandpass filter and a IR cut filter, we block Visible and IR while allowing UV light to pass.
• Fluorescence or any Photoluminescence occurs when a material absorbs electromagnetic radiation of a discreet wavelength and then emits a different, generally longer wavelength (lower energy) light along with a little heat.
• When a subject absorbs UV light, it excites electrons to a higher energy level. In this excited state, the electron is unstable. To return to its ground state (where it started), it emits the absorbed energy as visible light and heat. That's why stuff glows in the dark.

Any questions? Just drop them in the comments.