Fluorescence

Category: Pages
Published: Saturday, 16 March 2019 10:55

Ultraviolet Fluorescence

Ultraviolet light (UV) is invisible to the human eye but when certain substances are exposed to it, they emit visible light. I became interested in photographing fluorescence when a friend told me that scorpions are blue under UV light.  People rarely see scorpions because they are well camouflaged but where I live on the outskirts of Sydney they are quite common and are easy to find if you search the leaf litter at night using a UV light.

My initial photos were disappointing because the backgrounds looked artificially coloured. I discovered that most ultraviolet sources, also emit visible light and most cameras  record this light and also reflected UV light as unwanted colour. High output flashlights such as the ones below can be purchased online for around AU$50 (2023). They emit 365 nm ultraviolet light and include a 'ZBW' filter to block visible light. A "UV(0)" filter can also be used on the camera lens to prevent reflected UV from reaching the camera sensor and producing false colours.

 

 UV flashlights

 

 

Lichen growing on sandstone 

   

Diamonds - visible and UV light

 

Marbled Scorpion - UV exposure for 6 seconds at f16 and fill flash. Nikon D750, 180mm lens with UV0 filter, extension tube and tripod

 

Feathers - Feathers of a fledgling Powerful owl and a Sulphur-crested Cockatoo - visible and UV

 

 

 Australian $5 note - visible and UV

 

Eggs - visible and UV

 

 

 Dahlia flowers - visible and UV