20D/30D predictive focusing?

Does 20D/30D still adjust focusing in AF Servo mode after shutter release is fully depressed?

I often run into action shots where the focus is 0,5m behind the object coming towards you...?

Just set smaller aperture or upgrade to 1DmiiN?

.... or learn to do manual focusing. We old-timers did that all the time with moving subjects - long before anybody even thought that autofocus would ever even be possible, much less reasonably practical.

In my opinion, too many people today get brainwashed with technology to the point where they completely forget that manual control of things is not only possible but many times the best solution.

How would you use manual focusing for, for example, a runner coming towards you? Those situations seems frighteningly difficult.

curiousgeorge wrote in post #2365848
How would you use manual focusing for, for example, a runner coming towards you? Those situations seems frighteningly difficult.

Once you have familiarized yourself with how much motion to apply to the focusing ring on the lens, it's really quite easy to follow motion that is travelling in a predictable direction or pattern. All it takes is a lens with a decent manual focusing system (and not all lenses are suitable - particularly the 18-55 "kit" lens and the 50 f/1.8 ) and a little self-training.

curiousgeorge wrote in post #2365848
How would you use manual focusing for, for example, a runner coming towards you? Those situations seems frighteningly difficult.

Focus on a point at the same distance as the object, ie lines on the road, or the grass in that area. Once the subject gets to that distance, pull the trigger. Then continue to chimp for a minimum of 5 minutes.

curiousgeorge wrote in post #2365848
How would you use manual focusing for, for example, a runner coming towards you? Those situations seems frighteningly difficult.

Practice,practice and pratice...............

SkipD wrote in post #2365904
Once you have familiarized yourself with how much motion to apply to the focusing ring on the lens, it's really quite easy to follow motion that is travelling in a predictable direction or pattern. All it takes is a lens with a decent manual focusing system (and not all lenses are suitable - particularly the 18-55 "kit" lens and the 50 f/1.8 ) and a little self-training.

It also helps if you have some sort of MF aid. Like a split prism focus screen. Using a 20D/30D and the stock screen is really a challenge to manual focus. It can be done, but it takes practice. I had to rely on it at a wedding in a dark hall. The 28-75 just wouldn't lock in AF so I had to go full manual. FUN.

i never got into autofocus, i found it always too slow and it always was focusing on something i didnt wanted. But that is maybe because i was rised on analog camera and had to use it long after digital was already available or maybe because digital cameras i had was poor...
But on moving objects? that cannot ever work.

Most problems with AI Servo come from either not choosing which AF point you want to use and letting the camera pass focus off to something other than the subject or not tracking the subject long enough before taking the shot.

If you choose which AF sensor you want to use you have to track the subject with that sensor on the eyes or wherever you want sharpest focus to be.

If you track the a subject that is moving in a fairly constant direction and speed for a long enough time, AI Servo usually does a reasonably good job of predicting where focus should be when the shutter fires.

I used to shoot sports with manual focus and the most reliable method was to pre-focus on where you predicted the subject would be. You then followed the subject with your camera and pressed the shutter just before it got to sharpest focus. You had to be a little early because there is a tiny fraction of a second after you press the shutter while the mirror flips up before the shutter actually fires.

The other method with manual focus was to track focus as the subject moved and try to keep the focus movement with the left hand constant while the camera fired. This takes a lot of practice to get good at and is never 100%.

Perhaps I described my question bit too unclearly...

I know this 'in the same ballpark' prefocusing, center point focusing and stuff, but I'd like to know if these bodys continue focus tracking when shutter release is pressed i.e. DOES the focusing stop right there and let the subject come out of focus already when taking the picture.

http://www.photoworksh​op.com/canon/EOS_Digit​al.pdf has something about this with 1D mkii in page 7.

edit: ScottE: Thanks, that was quite accurate what I was looking for. Took me too long to search the right file and write....