Canon 75-300 IS at 255mm
f5.6 at 1/800 second
This image is, perhaps, from doing it the hard way, and while I can't personally recommend that, it does work on occasion. Ruby-throated hummingbirds (Archilochus colubris) are hyperactive little avians, like most hummingbirds, and can largely be counted on not to hold still, even when feeding from a salvia flower — they might hold position for as long as two seconds, typically less, before moving on to another flower, which probably is not the one next in line either.
Standing still about five meters (16 feet) away under the thin shade of a tree in the North Carolina Botanical Garden in Chapel Hill, I was tracking the activities of at least a pair as they made occasional visits spaced 5-15 minutes apart. The lens was set for manual focus, since with subjects so small and quick it is virtually guaranteed that autofocus will lose its lock and begin tracking through the entire length of its travel trying to find the subject again, or more likely simply lock onto the surrounding foliage and refuse to budge away. I selected Shutter-Priority (TV) mode at 1/800 second to both freeze their movement and counter any shake I might have from handholding the camera, and this necessitated a higher ISO in the lighting conditions. Many images from this session lack critical sharpness as I was unable to pin focus down in the very brief amount of time the hummingbird would pause, and every time it moved to another flower it was a different distance so re-focusing was necessary.
As you can see, even 1/800 second isn't enough to prevent their wings from blurring, but that's okay because the blur is both natural and expected. I would like to take credit for my consummate skill, but there was a certain amount of luck involved in getting the focus nailed with such a nice position, even given the light angle from the sun. Yes, I'm pleased, and it was worth the wait in 95° (or is that 35°?) weather.