1Ds Mk III

I'm trying to get close-ups of a hummingbird... a 180 mm micro lens mounted on my 1DS MkIII, using a tripod with a remote shutter, at a distance of about 30".
I set the thing up and wait for the bird to enter the FOV, then push the shutter...a lot, think AI Servo Mode.

I can't get the auto focus to follow the bird around the field of view. Ya gotta remenber at that distance of 30" that hummingbird occupies about 20% of the FOV.
I think that it should be able to follow, but often it locks onto the background follage, 50" away.

Now, I'm thinking that it may be the way my Custom Functions, with regard to auto focus, are set up. I know that the 180 macro doesn't AF very quickly, but this does suck.
Any suggestions on fixing the problem?

Pre-focus your lens to where you want to be in focus, then turn off your lenses AF. Wait for the humming bird to get into your picture frame and take the picture. Make sure you have enough depth of field so your humming bird is all in focus.

Take Care,
Cheers, Patrick

Pre-focusing does work but you're only working with a 1/2" DOF which is quite limiting.

I also pre focus then turn off AF. I set up a feeder with only one port that isn't taped up. Generally, the hummingbird will hoover in the air between sips directly in front of that port. Then I can pre focus on the space where the bird will be hoovering. I also use a wireless flash so I can get my aperture to f8. I use my 300 f2.8 lens for these shots and use extenders as well.

Were you trying to get closer than this?

your technique is how I captured this one

How should my custom functions be set up for AF?

Gene you did nail that sucker and your use of lens was spot on...my goal is to take a series of then and then blend them into a panorama like my GB Herons and Egrets,
anyway a call to customer support indicates that my problem lies with the lens...being a macro, it doesn't AF fast enough to achieve focus. My Custom Functions were fine.
They said that using my 300mm with extensions tubes would work better...we shall see.