Photographing Bioluminescent Roridomyces
Some glow-in-the-dark shots of a special species of Roridomyces my friend found for me in Gombak, Kuala Lumpur.
From the years of photographing bioluminescent species of mushrooms, I’ve always found Roridomyces to be the trickiest. It’s always a gamble. Typically, either the stipe, mycelium, spores, or cap glow in any order. Or not at all, and I’m left in the dark.
Roridomyces is a species in Family Mycenaceae with a wide distribution found in both temperate and tropical environments. I often saw them in New Zealand, commonly called Austro Dripping Bonnets, given their defining characteristic: slimy, sticky gel that covers the stipe.
I usually only see them glowing in the stipe and very seldom see the cap or gills glowing. So it came as a surprise when I was able to capture the caps glowing in what I suspect are Roridomyces lamprosporus.
Each photo involved a different setting. So, while I can see these glowing faintly with the naked eye, capturing them on camera requires adjusting the aperture, ISO, and exposure time. Some were shot at f/5.6 to f/14 with an ISO1600 to 6400 for 1 min to 7.5 minutes.
Aperture (f-stop): A higher f-stop number (like f/7.1 to f/14) brings more of the mushroom into focus. But this also means it takes longer to let in enough light to show the glow, so I need a longer exposure time.
ISO: Higher ISO settings (like ISO 6400) make the camera more sensitive to light, which helps capture the glow faster but also adds "noise" (graininess). Lowering ISO reduces noise but requires longer exposure times.
Exposure Time: I start with ISO 6400 and a 1-minute exposure to check the brightness. If it’s too noisy or not bright enough, I adjust from there.
To get the best shot, I connect my iPhone to my camera with the OI.Share app, which lets me see updates on my phone screen every minute during long exposures. When the photo looks bright enough, I stop the exposure.
Then I have to wait again for the camera to process and reduce noise – this takes the same amount of time as the original exposure. So, if I shoot for 5 minutes, I need to wait another 5 minutes for the noise reduction to finish.
One last trick I found was to take photos further away from the subject so that you can use a lower f-stop number yet still get everything in focus. Then crop the image later. Although it is best to shoot in RAW, sometimes JPG is decent enough.
You can also attempt to stack images (manually shifting the focus point) and take a few at varying depths to get the entire subject in focus, but I’ve found my hands aren’t as steady, and slight movements to the camera and tripod don’t align well in post-production.
