Tripds, Timers, and Hummingbirds
4 August 2020
Almost all of my pictures are taken “by hand”. That is, I spot the bird, point the camera, adjust assorted settings, and take the picture. (Yes, there are lots of useless shots that way, but pixels are cheap.) Sometimes, though, I “cheat”. There's a rose of Sharon bush I know of that ruby-throated hummingbirds like to visit in August, but I can't easily predict when. Accordingly, I set up my camera on a tripod, aimed it broadside at one flower, and set the interval timer to take a shot every 15 seconds. 400 pictures later…
I didn't want to examine 400 pictures carefully, though. Accordingly, I wrote a small script that turned them into a short movie. Any time I saw something dark flicker through a frame, I noted where, and went back and reviewed those pictures by hand. (Technical details: I used a high shutter speed, to freeze wing movement, and I used a relatively small aperture to get the entire bird in focus. If you look closely at the picture, you'll see that even 1/1000th of a second exposure wasn't fast enough—I should have gone to 1/2000 or even 1/4000. To make the “movie”, I used ImageMagick to rescale each picture to 25% of the original, converted it to a GIF, and wrote the filename and timestamp in the upper right of each one. I then combined all 400 GIFs into an animated GIF, with each frame lasting 40 ms. That's long enough that I can see the flicker of a hummingbird, and since most of the characters of the filename don't change between frames I can see the approximate point in the sequence. I have to view ~15 shots quickly to pick out the ones I want.)
Ruby-throated hummingbird (female)
Of course, there are many insects who like flowers, too. And the flowers don't mind that much—look at how pollen-coated they are.
