Behind the shot: Caiman Under Stars is a blog post from the Pantanal category.

Behind the shot: Caiman Under Stars

Posted by Will on

Our Caiman Under Stars set of photos was shot over the course of three nights last summer. We were in the Pantanal – a massive wetland region of Brazil, over 10 times the size of the Florida Everglades.

Usually we aren’t content with just taking photos during the day so we often go out in search of nocturnal wildlife. On one of our night walks we came across a swampy area where caimans were lying in a channel waiting for fish to swim past. It was a very dark night with no moon but plenty of stars overhead. I’m not sure where the inspiration came from but we decided to try and photograph a caiman with star trails in the sky above.

Caiman Stars
Caiman under the stars

It would have been easy to get the shot by first photographing the caiman and then compositing a second shot of the stars. However, we wanted to achieve the effect in a single exposure (so that it would be eligible for competitions amongst other things).

Composing the shot by the light of a headtorch was the first challenge. We were using a 16mm lens on a full-frame Canon 1Ds Mk III so the second challenge was getting close enough to the caiman!

We knew from experience that we could get a suitable star trail image using a shutter speed of 40 minutes, aperture of f/4.5 and ISO of 200. Based on these settings, we manually controlled the output of an off-camera speedlite flash to correctly expose the caiman in the foreground. This produced a single flash at the start of the exposure which froze the caiman’s initial position on the sensor. For the remainder of the exposure the caiman could thrash around chasing fish as much as it liked without ghosting the image (of course this only worked because the foreground was completely dark – if there had been a moon or stray torch beams then there would have been ghosting).

Caiman Star Trails
Caiman fishing at night in the Pantanal

One last detail – at f/4.5 it would have been impossible to have both the stars and the foreground in focus. To get over this we first focused on the head of the caiman, started the exposure, triggered the flash and then shifted the focus to infinity as quickly as possible!

Once we set the camera off we had to wait for 40 minutes with our flash-lights dimmed, swatting mosquitos and keeping an eye out for jaguars before we could move on to the next shot. We would take around 4 or 5 shots before midnight then flop into our beds with our alarms set for pre-sunrise so that we could enjoy the good morning light. Needless to say, we left the Pantanal exhausted!


  1. John Doyle said: February 23, 2009 at 4:04 pm

    What can I say… exceptional……How lucky you are to be afforded the opportunity to do something like this.. and to produce such fantastic results…Well done everyone…………John

  2. Madeleine Calaido Weber said: February 24, 2009 at 9:20 pm

    Absolutly stunning, never seen before! great image idea! cheers Madeleine

  3. William Bushe said: February 28, 2009 at 1:45 am

    Hi Guys,

    I was suspicious of the star trails and cayman being in a single exposure… then I read the explanation, nice technique.

  4. Alan Dean said: February 28, 2009 at 5:03 pm

    Great work guys – definitely thinking outside the box. And even more so for sharing the idea. Cheers, Alan

  5. Steve Gill said: February 1, 2010 at 9:28 pm

    Great composition and wonderful lighting make an unusual and evocative image.

  6. Sebastian Kennerknecht said: February 10, 2010 at 4:46 pm

    Wow. Truly inspiring images. You guys are more than deserving of all the attention you are receiving.

    I have a question which I should probably know but I don’t so I figured I would ask.

    You say that you mannually calculated the flash output considering your exposure of 40 minutes, f/4.5, ISO 200. How is this done?


  7. Sarah said: April 27, 2010 at 4:26 pm

    Thanks for asking Sebastian, I was thinking the same. It is something I have been wanting to do for ages, get some great shots of the star trails but exactly how do you set it up. Also I was worried my camera would let damp enter being outdoors for so long ….????

  8. Will said: April 27, 2010 at 4:44 pm

    Hi Sebastian/Sarah. You can figure out the exposure by putting the ISO right up and opening up the aperture fully. Then use trial and error to get the correct settings for the stars. Now keep halving the ISO and doubling the exposure time until you get the ISO to a reasonable value. You can also close the aperture by a few stops if you want, again doubling the exposure time for every f-stop.
    If the air is very moist then you might get condensation forming on your camera. The best way to prevent this is to keep your camera warm with some heat pads.

  9. Cornwall Photography said: June 10, 2010 at 12:28 am

    A great shot and thank you for explaining the method you used to get the result. Really simple when you know how. (maybe not really simple)

  10. Joey Rico said: June 10, 2010 at 5:01 am

    wow!!! great shot!!! was always wondering how these shots were taken…

  11. Maud Guye-VUillème said: June 14, 2010 at 7:56 am

    Brilliant ! Love the story 🙂

  12. Deborah Flowers said: July 1, 2010 at 7:09 am

    These are amazing and awesome images!!! Can I set my shutter open for 40 minutes???
    The story and explanation details is an exceptional inclusion to these fabulous photographs!
    Thank you so much for sharing!

  13. Brian Pflanz said: December 18, 2010 at 9:51 pm

    Amazing shot! I would not have been so concerned with the mosquitos, I would be watching the Caiman!

  14. Ken McCullough said: March 25, 2014 at 12:38 pm

    Could I ask what camera and lens you were using please?

  15. niher ranjan das said: May 12, 2016 at 8:18 am

    You wrote your article ,’it would have been easy to get the shot by first photographing the caiman and then compositing a second shot of the stars. However, we wanted to achieve the effect in a single exposure ‘, I ask you that was it multiple expose of 40 min that first attempt caiman & second attempt stair trails capture ?

  16. niher ranjan das said: May 12, 2016 at 8:28 am

    I understood that two attempt you completed the shot in single exposure but how time stay focus on caiman & how time stay focus on stairs ? But total 40 min single expo

  17. Astolfo Feregrino said: July 19, 2016 at 5:11 pm

    Wow, I Bennett following you in FB, but this is the first time you almost make me cry. I imagine every single minute of your experience and the results are marvelous. In September I have a trip to South Africa and I hope to take some long exposures, I’m still learning, is an expensive hobby but is a very good way to have connection with nature, would be amazing to learn from you in a trip. How can I get a print photography from you. I like to have that one. The croc one with your autograph. Thanks so much for your art. ASTOLFO FEREGRINO

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