Feature Video

Alien Transformations Under Ultraviolet

29 February 2016
Ultraviolet (UV) macro photography is a highly niche and challenging photography genre, largely because of the difficulty in finding a suitable subject, in getting the subject to be cooperative, and to get the exposure just right. Most examples of UV fluorescence in the world of arthropods had been restricted to scorpions until in recent years when I saw some examples of UV fluorescence in harvestmen by Paul Bertner. Since then, my group of photography buddies have been experimenting with UV exposures during our field trips and managed to land some pretty alien, mind-blowing results!

Most of the photographs were taken in Singapore unless otherwise specified. Thanks to my friends who have been constantly trying out UV on the various subjects that we found, especially Melvyn and Chris. Thanks to Javed Ahmed for valuable inputs in each of the posts that I write. Without them, this series would have been way less interesting!

Equipment for UV Photography

I have been receiving many questions about the equipment used for the UV photos and thought it would be better to answer them here. UV fluorescence is not UV light, so the presence of a UV filter does not affect the photo. The fluorescence is visible to the naked eye so all you need is a UV emitting light. I am using many different models of UV lights, many of which are brandless and from China. Most give varying results even within the same model, so I am unable to recommend any “best” one. For a start, try UV lights with a shorter wavelength in the range of 365nm and experiment from there. If you do attempt UV fluorescence photography, please read the warnings regarding use of UV lights below.


Prolonged exposure to certain wavelengths of ultraviolet can be dangerous to human skin and eyes, and possibly to some subjects as well. Please be aware of the risks involved before working with various ultraviolet wavelengths, and avoid using extended exposures.

    White Light
    Ultraviolet & White Light
    Scorpion (Tityus sp.) - Tityus_DSC_3389
  1. Scorpion (Tityus sp.)

    Ultraviolet light has been used for spotting scorpions for a long time, as they fluoresce brightly under ultraviolet and can be spotted easily from a distance. Your first sighting of the fluorescence would almost definitely be mind-blowing as they would appear to be glowing brightly in the dark!

  2. White Light
    Harvestman (Cosmetidae) - Opiliones_ESC_0149
  3. Harvestman (Cosmetidae)

    Over time and experimentation, we found that several harvestmen would produce a faint fluorescence as well, and on various parts of its body for some. This is a less common example where the entire body fluoresces.

  4. White Light
    Big-Headed Bark Spider (Caerostris sp.) - Caerostris_DSC_4857
  5. Big-Headed Bark Spider (Caerostris sp.)

    One of the first few spiders exhibiting ultraviolet fluorescence was this cryptic Caerostris. It wraps itself onto tree branches in the day, blending in perfectly. The ultraviolet fluorescence here exposes the spider while leaving the branch in its natural colour.

  6. White Light
    Ultraviolet & White Light
  7. Spiny orb weaver (Gasteracantha sp.)

    The abdomen of Gasteracantha exhibits a strong fluorescence in the sclerotised areas, leaving its muscular depressions in its natural dark colour. This allows us to view the distribution of muscular depressions easily.

  8. White Light
    Ultraviolet & White Light
    Bird dung spider (Pasilobus sp.) - Pasilobus_DSC_3543x
  9. Bird dung spider (Pasilobus sp.)

    Looking like a piece of dung, this spider transforms into a beautiful blue jewel under ultraviolet, exposing the locations of the muscular depressions on the abdomen as well.

  10. White Light
    Ultraviolet & White Light Behind
    Huntsman spider (Pandercetes sp.) - Pandercetes_DSC_9674b
  11. Huntsman spider (Pandercetes sp.)

    Some huntsman spiders have a moderate fluorescence that is stronger in the legs and carapace and occasionally on the abdomen as well. The camouflage is also easily exposed in the example.

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    Ogre-Face Spider (Deinopis sp.) - Deinopis_DSC_8273
  13. Ogre-Face Spider (Deinopis sp.)

    While most spider eyes are really small, their eyes almost always fluoresce. The ogre-face spider has exceptionally large anterior median eyes that are ideal for showcasing this fluorescence. It almost looks creepy!

  14. White Light
    Ultraviolet & White Light
    Black armored trapdoor spider (Liphistius sp.) - Liphistius_ESC_0135
  15. Black armored trapdoor spider (Liphistius sp.)

    Some spiders are completely black and it can be extremely difficult to discern the location of its eyes. Ultraviolet reveals the radical eye positions clearly in this male Liphistius from Malaysia.

  16. White Light
    Crab spider (Runcinia sp.) - Runcinia_DSC_1699
  17. Crab spider (Runcinia sp.)

    Many crab spiders exhibit a fairly bright fluorescence under ultraviolet, especially those that ambush in or close to flowers. Some flowers are known to fluoresce with various hidden patterns under ultraviolet, so there might just be a logical link between the two!

  18. White Light
    Longhorn Beetle (Anancylus griseatus) - Anancylus_DSC_7710
  19. Longhorn Beetle (Anancylus griseatus)

    Beetle eyes tend to show a faint glow under ultraviolet, and is easily shown in cerambycids with large compound eyes.

  20. White Light
  21. Longhorn Beetle (Cerosterna sp.)

    Another cerambycid with part of its abdomen fluorescing lightly as well.

  22. White Light
    Bearded palm weevil (Rhinostomus barbirostris) - Rhinostomus_ESC_0205
  23. Bearded palm weevil (Rhinostomus barbirostris)

    This funky and large weevil from Belize is a good example to show others exactly where the eyes are positioned and how it is not “just a ball of eyes” with a snout sticking out.

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    Millipede (Diplopoda) - Diplopoda_DSC_8650
  25. Millipede (Diplopoda)

    A small number of millipedes can fluoresce brightly under ultraviolet, with the legs showing the brightest fluorescence. I have not determined the species that do fluoresce, but the brightness can be comparable to that of scorpions.

  26. White Light
    Caterpillar - Caterpillar_DSC_3622
  27. Caterpillar

    A good number of lepidopteran larvae show varying degrees of ultraviolet fluorescence. With some trial and error, we found some pretty amazing looking fluorescence in this spiky fellow!

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    Net-Winged Beetle larva (Lycidae) - Lycidae_DSC_7383
  29. Net-Winged Beetle larva (Lycidae)

    This patch of lycid larvae was a surprise find, with fluorescence turning the scene into what looked like a water painting.

  30. White Light
    Stink bug nymphs (Pentatomidae) - Pentatomidae_DSC_2524
  31. Stink bug nymphs (Pentatomidae)

    Pentatomid eggs fluoresce well under ultraviolet as well. Sometimes, the nymphs will display varying degrees of fluorescence as seen in this example from Peru.

  32. White Light
    Stick insect (Prisopus sp.) - Prisopus_DSC_7265
  33. Stick insect (Prisopus sp.)

    In Belize, we found a cryptic stick insect that blended exceptionally well into its surroundings, and discovered that the camouflage failed beautifully under ultraviolet!

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    Scale insect (Paralecanium sp.) - Scale_Insect_DSC_1488
  35. Scale insect (Paralecanium sp.)

    This tiny scale insect spells alien when viewed under ultraviolet. Completely out of this world!

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    Katydid (Tettigoniidae) - Tettigoniidae_DSC_1572
  37. Katydid (Tettigoniidae)

    This leaf-mimic katydid flattens itself on a leaf to conceal its silhouette, but exhibits a venous fluorescence.

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    Leaf-mimic katydid ovipositing (Tettigoniidae) - Tettigoniidae_DSC_7628
  39. Leaf-mimic katydid ovipositing (Tettigoniidae)

    The fascinating venation of this ovipositing leaf-mimic katydid is easily highlighted with ultraviolet.

  40. White Light
    Mushroom (Fungi) - Fungi_DSC_9186
  41. Mushroom (Fungi)

    A recent discovery was an inconspicuous brown mushroom on the forest floor that fluoresced brightly under ultraviolet. Not sure why, perhaps someone reading this would know?

  42. White Light
    Tortoise beetle (Aspidomorpha sp.) - DSC_2521
  43. Tortoise beetle (Aspidomorpha sp.)

    On its own, tortoise beetles are already mesmerisingly cute. Its elytra lights up well under ultraviolet!

  44. White Light
    Stick insect (Necroscia punctata) - DSC_5317
  45. Stick insect (Necroscia punctata)

    Under ultraviolet, this spotted flying stick displays a dazzling mix of colours.

  46. White Light
    Red tent spider (Cyrtophora unicolor) - DSC_0946
  47. Red tent spider (Cyrtophora unicolor)

    An otherwise boring looking “strawberry” turns into a blue gem!

  48. White Light
    Huntsman spider (Gnathopalystes sp.) - DSC_1339b
  49. Huntsman spider (Gnathopalystes sp.)

    Enchanting fluorescence on this huntsman spider.

Why is the reason for ultraviolet fluorescence?

So the biggest question that many may have, is WHY? Why do certain species of arthropods fluoresce under ultraviolet? Is there a biological purpose? In 2013, Gwen Pearson had written an article based on some of my UV photos on WIRED, and DIYPhotography.net published a UV photo series from me in 2015. Other than these, articles and information on UV fluorescence and photography have been rare.

Ultraviolet macro photography requires some skill, lots of luck, and a good amount of patience. I’ve covered the technical aspects in detail in last year’s Borneo Bootcamp and Bugshot Belize, and while I do not have advanced workshops planned for this year (yet!) I hope to incorporate UV photography into the syllabus of all of my advanced macro workshops.

Please share any other examples of UV fluorescence you may know of in the comments section below. For queries, comment or mail me at nicky@bay.to.

If you are interested in my other macro photography work, do check out some of my earlier photo articles below. I also have an on-going Spider Photo Exhibition at the Senckenberg Natural History Museum in Frankfurt (Germany) until 7 January 2017, do pop by if you are around the region!

  1. Reply

    Ankan Das

    12 May 2021

    Sir, I am from Bangladesh. I follow your every images. I want to know about uv macro photography. Do you have any tutorial video about on this subject?

    • Reply

      Nicky Bay

      17 May 2021

      Sorry I don’t have any video tutorial on this. But you just need to shine the UV light on any subject. If there is visible fluorescence, then take your picture without flash. Use a tripod with long exposure if the fluorescence is dim.



Hi my name is Nicky Bay. I am a macro photographer, instructor and book author, travelling the world to document the vast micro biodiversity that nature has to offer. Follow my updates and discover with me the incredible beauty and science behind our planet's micro creatures!

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