Fluo Photography

Golden Mantis Shrimp opt

Fluorescence diving is hot. Here's how to photograph its magical glow 

Fluorescent night diving, also known as fluo or fluoro dives, have been on offer at select dive centres and resorts for a number of years now. I did my first fluo dive in 2010 while working as a photo pro at a dive resort in the Philippines. I was interested in capturing images that were a bit different – and fluo photos certainly fit the bill. I used an ultra violet (UV) dive light and was immediately hooked on this freaky, psychedelic night diving that made dull brown-coloured corals glow bright green. I then started to research underwater fluorescence further and came across US based company Nightsea operated by Charles Mazel, who has been a pioneer of underwater fluorescence. I set up a fluo diving operation at the resort, using Nightsea equipment, introducing many divers to this unique style of night diving. I also switched from UV to a specially filtered blue light, as this seemed to be better at revealing fluorescence – at least in the Indo-Pacific region where I was diving. Since then, I've completed many fluo dives with my camera, and found some very cool, glowing creatures, in the process. 

Before we can photograph fluorescent creatures, we need few pieces of specialised equipment so we can see the fluorescence ourselves, enabling us to find suitable subjects. An ‘excitation light’, which stimulates the organisms to fluoresce, is required. This can be a normal light with a blue (dichroic) filter, a UV light or, ideally, a blue light (which also has a dichroic filter) such as the Light & Motion Sola Nightsea. However, this blue light is reflected back at us and overpowers the more subtle fluorescence, so a yellow barrier filter is placed over your mask to block it and leave all the fluorescent colours visible.



Striped triplefin A striped triplefin has a pattern of movement, making subject not too difficult to shoot. Watch were it regularly settles (ideally on a non-fluorescent background) and set up your shot from there. If you spook your subject and it moves, be patient, it should return to the same spot. 

Fluo - Nikon D200 in Subal ND20, Nikkor 60mm, 2 x Inon Z240s - f/11 - 1/250th - ISO 640, Nightsea Filters; White - Nikon D200 in Subal ND20, Nikkor 60mm, 2 x Inon Z240s - f/32 - 1/125th - ISO 100



Freckled Frogfish This is the only frogfish I've seen that fluoresces - and it's quite a strange shift in colour from purple-pink to orange. The fluorescence was not that strong with this species, so make sure your background doesn't overpower the subject, taking away the impact of the shot. 

Fluo (below)- Nikon D7000 in Subal ND7000, Nikkor 60mm, 2 x Sea & Sea YS-250 Pros - f/8 - 1/200th - ISO 800; Nightsea Filters; White (left) - Nikon D7000 in Subal ND7000, Nikkor 105mm VR, 2 x Sea & Sea YS-250 Pros - f/18 - 1/320th - ISO 320



To capture fluorescence on camera we need some special equipment added to our set-up. A blue (dichroic) excitation filter is mounted over the strobe to stimulate the fluorescence and a yellow barrier filter is needed on the camera lens – either externally on the port or internally, directly on the lens. This serves the same purpose as our mask barrier filter. My preference is for an internal filter, as I dedicate my dive to fluo photography, rather than switching back and forth from fluo to normal white light which I feel breaks concentration and is less productive. 

Our eyes are more sensitive to light than the camera sensor, and fluorescence can be a fairly weak effect – with the exception of some of the brightly glowing green corals – so we need as much strobe power as possible. I use three strobes, allowing me to step down the aperture for a greater depth of field. If you are considering capturing some fluo video as well as stills, then two or more lights with a wide beam are an alternative to strobes and will allow you to cover both disciplines. Shooting with continuous light does require slower shutter speeds though, as the light output is not quite as powerful as the quick burst of light that a strobe delivers.There are a number of different equipment manufacturers that make fluorescent gear and camera accessories, namely Nightsea, Light & Motion, FireDiveGear, Glow Dive, Dyron and iDive-Site – plenty of options for varying budgets.


Hydroid Decorator Crab opt

Hydroid decorator crab Fluorescing chlorophyll, contained in the algae covering the coral that this hydroid decorator crab is climbing, causes the red background.

Nikon D200 in Subal ND20, Nikkor 60mm, 2 x Inon Z240s - f/8 - 1/1250th - ISO 800. Nightsea Filters



urchin clingfish These diurnally active fish are constantly on the go during daylight hours, making them tricky to shoot. But they settle down at night, resting inside the spines of the black longspine sea urchin. They don't fluoresce brightly though, so you need a good eye to spot them.  

White (top) - Nikon D7000 in Subal ND7000, Nikkor 105mm VR, 2 x Sea & Sea YS-250 Pros - f/11 - 1/200th - ISO 200; Fluo (bottom) - Nikon D7000 in Subal ND7000, Nikkor 105mm VR, 2 x Sea & Sea YS-250 Pros & 1 x Inon Z240 - f/16 - 1/320th - ISO 800, Nightsea Filters; White 



Dusky Nembrotha Hardly a dull subject to begin with, the red-coloured portion of this dusky nembrotha nudibranch, which can be quite variable, fluoresces brightly. Be careful with brightly fluorescing subjects like this, to ensure that you do not blow out the highlights, losing detail that cannot be recovered.

White (top)- Nikon D7000 in Subal ND7000, Nikkor 105mm VR, 2 x Sea & Sea YS-250 Pros - f/11 - 1/320th - ISO 320 Fluo (bottom) - Nikon D7000 in Subal ND7000, Nikkor 60mm, 2 x Light & Motion Sola Nightsea - f/10 - 1/40th - ISO 800, Sola NightseaFilters; 



Shooting fluo is a bit trickier than normal white light and you will encounter some unique challenges. First, light levels are greatly reduced, as you only see what fluoresces, leaving everything else in the dark. You should therefore be comfortable diving with these limited light levels. Excellent buoyancy control and spacial awareness is essential to avoid damaging fragile marine organisms. You should also be very familiar with operating your camera and be able to change the settings without looking at the controls. 

On certain subjects with limited contrast, auto focus can be a problem causing the lens to ‘hunt’, especially on compact cameras and older model DSLRs. A good fluo light with a wide, even beam really helps the camera's AF system. 

Forgetting to remove your mask visor when shooting can be a problem. We need the visor to see the subject initially, but if you don’t remove it while looking through the viewfinder or at the LCD screen, the subject will appear darker than it actually is. This is especially relevant when reviewing images to check exposure, as a correctly exposed image will appear underexposed. This can lead to a bit of head scratching, as you wonder why the camera's histogram indicates good exposure, but the image looks too dark!



orangutan Crab There is no change in colour for this hirsute crustacean, but the fluo-lighting accentuates the already orange hairs, making it 'pop' from the background more than usual. It's not common to find these crabs in an elevated potion, so make the most of it if you do.

Fluo - Nikon D200 in Subal ND20, Nikkor 60mm, 2 x Inon Z240s - f/11 - 1/250th - ISO 640, Nightsea Filters; White - Nikon D200 in Subal ND20, Nikkor 60mm, 2 x Inon Z240s - f/32 - 1/125th - ISO 100


Brain Coral Symphilli opt

Brain coral The green colour comes from fluorescent proteins the coral tissues, while the red is from chlorophyll that is in the symbiotic algae that lives inside this brain coral species.

Canon PowerShot S100 in Fisheye FIX, Inon H100 Wide-Angle Lens, 2 x Inon Z240s - f/4 - 1/125th - ISO 400, Nightsea Filters


Lobed Cup Coral Lobop opt

Lobed cup coral Seek out subjects that emit a variety of fluorescent colours, like this green, orange and yellow lobed cup coral. For subjects laking macro-detail, this can make for a more interesting image than a monotone green. 

Nikon D200 in Subal ND20, Nikkor 60mm, 2 x Inon Z240s - f/8 - 1/200th - ISO 800, Nightsea Filters



As previously mentioned, we need as much light as we can squeeze out of our strobes, so I set them to the maximum power output and then angle them towards the subject. Edge-lighting is not required, as backscatter is normally minimal. Direct lighting is the way to go. When using strobes I set the shutter speed at 1/125th or faster. If shooting with continuous light you will probably need to use a slower shutter speed than this.

I control my exposure using aperture and ISO, initially setting it at around f/8 - f/11 and then adjusting depending on how much the subject fluoresces and the required depth of field. On my Nikon D7000 I normally begin with ISO 800, but quite often push it higher to capture the more subtle colours. A camera with good noise suppression is advisable and the noise reduction tool in post processing will get a little more use than normal.

I would suggest shooting in RAW, if your camera can. You can then set auto white balance and adjust as necessary in post processing, without incurring image degradation. Adjusting the white balance can have a big effect on how the image looks. I've also found that it's quite common to need to boost the exposure and contrast, while decreasing the shadows, to make the image pop. The target adjustment tool in the HSL panel can be handy on some shots, letting you selectively adjust the saturation and luminance of a specific colour.

Subject selection is important, as you want your subject to stand out from the background. Shooting a fish that fluoresces green in front of a brightly fluorescing green coral head will not provide the separation of subject from the negative space – it will be swallowed up in the glowing green background. Look for a fluorescent subject with a non-fluorescing background, or at least a background that has minimal fluorescence. 

As a general guideline, what looks dull under white light normally fluoresces brightly! There are exceptions to this, such as the dusky nembrotha nudibranch (Nembrotha kubaryana) and – I hear from friends in Lembeh –  the elaborately coloured paddle-flap scorpionfish (Rhinopias eschmeyeri). Coral reef environments provide lots of fluo photo ops, but muck dives too can throw up some unique fluo subjects. Strangely some creatures will only partially fluoresce, which can make for an interesting image, but can also leave the viewer wondering what they are actually looking at. Even more freaky are two identical fish, side by side, where one fluoresces and the other does not! It is not yet understood why this occurs.  



Lisa's mantis shrimp The 'spearer' variety of mantis shrimps live in burrows in the sand, and as sand does not fluoresce, it makes a good negative space from which your subject will clearly stand out. Make sure the focus is tack-sharp to show the intricate detail of the hairs and spots covering the body.

Fluo - Nikon D200 in Subal ND20, Nikkor 60mm, 2 x Inon Z240s - f/8 - 1/250th - ISO 800, Nightsea Filters; White - Nikon D200 in Subal ND20, Nikkor 60mm, 2 x Inon Z240s - f/32 - 1/125th - ISO 100


Anemone Hermit Crab D opt

Anemone hermit crab Some subjects fluoresce better than others. The shell of this anemone hermit crab appeared to be illuminated from inside and the anemone glowed too. While the shell of a white-spotted hermit crab only fluoresced red from the chlorophyll contained in the algae covering it.

Nikon D200 in Subal ND20, Nikkor 60mm, 2 x Inon Z240s - f/11 - 1/60th - ISO 800, Nightsea filters


Bubble Coral Physogyr opt

Bubble coral The semi-transparency of bubble corals allows the excitation light to penetrate the vesicles (bubble-like polyps) making it appear to glow from within. 

Nikon D200 in Subal ND20, Nikkor 60mm, 2 x Inon Z240s - f/11 - 1/1250th - ISO 640, Nightsea Filters


Tips & tricks 

• Practice operating your camera without looking at the buttons, so you become familiar with the controls. This will give you more time to get shots on the dive. 

• Give yourself time to get into the fluo photography groove, as it takes a few dives to get used to it. 

• Don’t get disheartened too soon if your images aren’t amazing, it takes a bit of practice.

• Avoid divers using white-light, as this wipes out the fluo effect. 

• Watch for the predominant colour in your shot, which is normally green (but can be red with certain subjects), and use your RGB histogram to check the relevant colour channel for overexposure. The luminance histogram does not always show this unless you have really blown out the highlights. 

• If shooting with a continuous light source, you can use the camera's light meter to check exposure before pressing the shutter release. If you use spot or centre weighted metering, move the metering point around the frame to check the exposure of the different areas.

• From a safety perspective, carry a white back-up light in case of emergencies and also to get the attention of other divers easily. Waving a blue light about isn’t that visible from a distance.



Love diving? You'll love these. Sign up today to immediately download our unique FREE gifts -

AROUND THE WORLD IN 80 WRECKS - DIVE's 70-page, beautifully illustrated, colour guide to the world’s best wrecks

SCUBA STORIES - DIVE's collection f real life stories where divers, who have got themselves into perilous situations, describe how they reacted and what actions they took to ensure they lived to tell the tale

PACIFICHighlights of the Pacific - Dancing mantas in Hawaii • The Best Diving in the World, Galápagos, Cocos, Malpelo & Socorro • Mass Spawning Events in Palau

Sidebar SUBSCRIBE spring 21 large2

Destinations Spotlight

Need inspiration for your next dive trip? Try one of our featured destinations from DIVE's travel partners.

sidebar philippines sidebar bahamas sidebar mexico sidebar fiji sidebar st helena 2020 Sidebar Egypt sidebar banner sabah sidebar banner belize sidebar banner south africa

DIVE Partners

sidebar banner egypt new ceningan divers ad 300x100 LH 300 min giphy subex Wakatobi Siladen Aggressor Fisheye Dive Worldwide gozo banner Arenui

Latest Articles

Read DIVE magazine

DIVE magazine is available to read on many devices. Simply click one one of the options below

PCMac final
Apple finalAndroid final

Like what you see?

Join us on social and keep updated daily...