exposure times for bioluminescence

Discussion in 'Nature' started by michael_ready, Jul 10, 2001.

  1. Greetings,

    I'm hoping to photograph a bioluminescent arthropod. They emit a
    visible but fairly dim light, similar to some bioluminescent fungi.
    What exposure techniques have proven successful with glowing
    mushrooms?

    Best,
    Michael
     
  2. Michael, I wish I could offer you some solid advice, but you are delving into an area that not too many photographers have a lot of experience with. Perhaps you will get lucky and someone with experience will chime in. However, in the meantime, my suggestion would be to experiment. You didn't mention what kind of film you want to use, but given the low level of emitted light, you are probably going to want to use a faster film to reduce the effects of recipricocity failure and color shifts. For slide film, the new Provia 400F is not bad and many print films in the 400 to 800 range are quite good. Anyway, your best results are probably going to come from your own experimentation. Try taking an initial reading with your camera's meter, bracket widely and take notes. Don't be afraid to experiment and you will likely find what works. Also, if you have good luck with it, let us know.
     
  3. I hope that yiu can find some good info on this. I tried to photograph bioluminescence in a ship's wake at the Galapagos Islands a couple of years ago with absolutely no luck at all.(Unless you include bad luck)

    Alex
     
  4. The only way that I can think of is to "fix" it, then make it glow by adding luciferin and ATP to the media. (the glowing effect requires three chemicals, luciferin, luciferase, and ATP [adenosine triphosphate].) Mount it on a slide, and take the photo. Talk to a biology professor at your local university. You'll probably end up with a 2-3 minute exposure at f/2.8 (you often lose a few f-stops in photomicrography).
     
  5. In response to the fixing suggestion, pretty much anything involving fixation will probably inactivate the luciferase (assuming that is even the reaction going on- there are other bioluminescent reactions), making this not work at all!

    How big are these arthropods, and what are they? I suspect you will require very long exposure times, even with a fast film. You'll need to keep them still somehow without inactivating the reaction; we once did an experiment using daphnia where we had to count their heartbeat; we made a little well out of molten wax on a slide, put in water and 1 daphnia, and then G E N T L Y pushed a coverslip into the wax until the animal was pinned laterally in position. With larger artemia, we actually superglued eyelashes to the back of the animal and embedded the other end in blu tak; both of these methods would probably allow too much movement, and I reckon that you will need to kill the animals somehow without inactivating the reaction. You may find that you might want some supplemental lighting as well as the bioluminescence to pick out other features in the animals; perhaps a digital camera would be quite nice in this instance if it can pick up light levels that low! (Certainly will save on film!). As others have suggested, lots and lots of experimentation, but I suspect you should get one decent exposure on a roll of 36 as a trial, and then work from there.

    good luck!
     
  6. stemked

    stemked Moderator

    I have had some experienec with luciferase induced with mercury in E.coli. The cells were trapped in a matrix and the light level was low. (In a dark room after about 10 minutes of letting your eyes adjust you could just see the cells in the latex glowing). I shot test shots with both 800 ASA Fuji (which we ultimately published) and 400 ASA Royal Gold; a 50mm f1.4 and could typically got somethings after 2 minutes (in a few rare cases as short as 30 seconds). We used a Pentax K1000 with the battery removed- We tried the lab's fancy Nikons but they couldn't handle the long exposures and the batteries kept going dead, leaving the shutters stuck open. The problem with a 1.4 f stop of course was then Depth of View which in our case needed to be at least 3.5 cm, which was a problem close up. I recall we did several very long shots (30 minutes- 60 minutes) at f16 to get what we needed. Fortunately our immobilized organisms really didn't mind the wait; I suspect that's another issue with your arthropod. I think the other posters are correct; you are going to have to try a bunch of exposures to really nail it.

    Good Luck!

    Doug

    Douglas Stemke, Ph.D
    Department of Biology
    Hanover College
     
  7. Low light photography is one area where digital shines, but you
    need to use a cooled CCD to prevent thermal noise and dark
    current swamping the image. That used to mean complex
    cryogen systems using liquid nitrogen or helium, but these days
    electric Peltier coolers are efficient enough to have taken over
    most applications.

    Made-to-measure cameras are available at a price, but if your
    budget is tight (whose isn't?) there are some interesting DIY
    projects which have been put together by the astrophotography
    community and which would be trivially simple to adapt to a
    microscope. A monochrome sensor and a set of colour filters
    would be the simplest way to get going. One such project is
    described in detail here:

    http://www.wvi.com/~rberry/cookbook.htm
     
  8. I shoot a glowworm yesterday with my D1X digital camera at life-size magnification, using f/5 at 10 secs @125 ISO. The shots turned out very well. Seems excessively long exposures are not needed for this application.
     

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