I like blurs, and I like images with dark shadows and deep greens (hence the name of this site). If you don't like blurs or darkish images, this one probably won't be to your taste but I hope you'll give it a chance :-). I was very happy to capture this image a couple of years ago at dawn on the Baru River on Costa Rica's south/central Pacific coast. I took a few images where I cranked up the ISO in order to obtain a faster shutter speed and a sharp bird but I didn't think these images were anywhere near as interesting. For me, the image below says much more about the essence of this lone green-heron flying up a rainforest river corridor as dawn breaks than any more literal, sharp focus photo could ever do.
Here's the thought process I went through while taking this photo.
First, this stretch of river is known for being an early morning flight path for green herons and cattle egrets. Starting right at dawn to about 30 minutes after, the photographer will get about 5 to 8 flybys, sometimes groups or pairs of cattle egrets and other times a solitary green or little blue heron. I definitely had a preconceived notion of what I wanted out of this image so the first order of business was to position myself properly. That meant standing across from a particularly shady section of the opposite riverbank. Because this section of the bank had much less early morning light falling on it than did the middle of the river, I knew that proper exposure for the bird would allow the riverbank to fall off into black.
Second, how was I to meter properly for the bird when one only got a five second or so window when a bird flew by? I used manual metering and set my exposure so that the opposite bank would be rendered at about 2 to 3 stops below average. I can't remember if I nailed it right away or if I adjusted a bit after the first flyby but you get the idea that by knowing the rough quantity of light falling on one part of the scene, you can set it to render the other tones properly.
Third, gear was a pretty easy choice. I had a Canon 40D and a Canon 5D to choose from. The full-frame 5D is much better with high ISOs but since I knew I wanted a blur, this wasn't an issue (see below). The 40D offered me two advantages -- a little bit of effective extra reach because of the APS-C/1.6x sensor and much better autofocus capability. So, 40D it was. In terms of the lens, I knew I wanted my trusty 300 mm. I could have shot it by itself and then cropped but I prefer to try nail compositions in-camera. So, I added a 1.4x teleconverter, which would make the bird a bit larger in the frame. Since I would be standing around a lot waiting for birds to fly by and because I wanted to keep my horizon level, I chose to work from a tripod.
Fourth, what about camera settings? I decided that 1/10 of a second was going to be a good shutter speed for the blur/pan effect I wanted. I could have set my camera in shutter priority mode but then I would run the risk of having the camera meter differently as I panned across the scene, ruining the careful thought I had already put into how to meter the scene. I'm not one of those photographers who thinks manual mode is the only way to shoot, but it is the only mode that allows you to be in complete control of all variables affecting exposure, which was important for this shooting situation. So, I went to manual mode, set 1/10 of a second, and then set my other two variables (aperture and shutter speed) so that they brought the meter to underexpose by two stops or so when I pointed the lens at the shaded opposite riverbank (see the second point above). I first decided that ISO 100, my lowest choice with the 40D, would help to slow down the shutter speed and would also produce the least noise. After that, I simply stopped down the aperture until I obtained the exposure value that I wanted for 1/10 second at ISO 100. That aperture turned out to be f22. That might have given me cause for concern because it had the potential to bring the background too much into focus. Nonetheless, since I knew the background would be falling to black and because I knew the image would be a pan blur in any case, the large depth of field that f22 would give me would not harm the image. In fact, f22 gave me a bit more leeway in terms of nailing the focus (notice that even though the bird is a blur, the focus is indeed right on).
Fifth, I had to decide how to move my camera during the exposure and how to achieve focus. Again, even though the bird is a blur, you can see some sharpness to the wing and the shape of the bird. If the bird weren't in focus, the image would not have been successful. I set my camera in Servo mode for the autofocus and selected the AF point that I knew would be closest to where I wanted to position the bird in the frame. The other issue was how to pan the camera to keep the horizon level. To do this, I leveled my tripod as carefully as I could and then simply took a couple of practice swings, panning the camera across my target stretch of river and snapping off a couple of frames. This allowed me to confirm that my horizon was level and also to check that my exposure was on for the background.
Sixth, for the composition, I knew that I wanted a bird in the upper left third of the frame. This would give the bird visual room to move and would also allow some green streaks of reflected forest vegetation to appear across the bottom of the frame.
Seventh, with all of this done, it was time to actually try to take a picture! My strategy was as follows. Whenever I would see a bird start to fly upriver, I would swing my camera downstream and start to focus on the bird, bumping and releasing the focus as it flew toward me. Once it got parallel to me and was flying across my target field of view I would snap the shutter a few times until the bird was angled past and thus not in a good position anymore for a photo. I would pan along with the bird, matching its speed, and kind of continue on as I shot -- kind of like following through when swinging a golf club or baseball bat. Had I been shooting a faster shutter speed, I would have set my camera on burst/continuous shooting mode. With my slow shutter speed, however, it wasn't necessary. I just tripped the shutter each time I though the bird was in a good position and I had decent focus.
I don't remember how many images I shot but it certainly wasn't a one and done kind of deal. Any time you shoot action, you're going to shoot plenty of pictures in order to get that one winner. You'll increase your chances greatly, however, by putting some thought into your image beforehand and being prepared when the time comes!
I hope you've enjoyed this post and the thought process behind the image. Successful nature photography is all about previsualizing an image (even when shooting action or capturing a fleeting moment), analyzing the tradeoffs that your previsualized image entails, and then making choices. Hopefully this little article will give you some ideas for the next time that you're out in the field photographing.
If you have questions or comments, please leave them below, and I'll respond as soon as I can.