Microfocus difference - Servo vs 1-shot?

I have a 1D-III (1D 3) body and shoot indoor sports with the canon 50 f/1.4, 85 f/1.8 and 135 f/2L lenses. I've dialed in the MF adjustment on static subjects but when shooting action, all 3 lenses tend to back-focus.

I have the AF moved to the back button. If I shoot a stationary player (or cheerleader the AF is spot-on. Hit the AF button momentarily, then take the shot.

If I'm shooting a player coming down court for a lay-up, I'll have 1/2 of the images in a sequence back focused.

I'm using center point AF only.

Is it normal to require different MF Adjust settings for server vs. one-shot AF modes?

It sounds as if you're releasing the AF button before firing the shutter release. This will be OK with stationary subjects. But with moving subjects the AF will stop tracking them when you release. In the time between releasing AF and firing the shutter the subject has moved towards you, forward of the plane of focus. Hence the shots appear back-focused.

One typically gets backfocused shots in the situation you describe from two sources:

1) You may have picked up the target and started shooting immediately. The more time you give the AF system before you start shooting, the more accurate it will be. If you can give it a solid half second, the performance should be good.

2) You may have allowed the AF point to wander off the target momentarily while tracking them. The servo focus is predictive, so giving the AF system constant data on the speed and location of the subject is important. If the AF point leaves the target for any reason, the data is worsened and the performance goes down.

Hollis_F - Sorry, I wasn't clear. I'm staying on the AF button when the action is continuous. The only time I press and release it is when I am shooting a static subject.

JeffreyG - I've seen the issue where shooting too soon gives you one or two OOF frames so I always strive to get AF going for as long as possible before starting to shoot.

Update - Tonight I shot a game but this time, I shift the lens MFA 5 points left for my main lenses. What a difference. Instead of throwing away most of my shots due to OOF, I kept most as they were in focus.

It is yet to be seen whether the new MF adjustments will mess up one-shot or static subject focusing.