40D Question

Hi all,

Assuming I am shooting at between 1/500 and 1/1000th of a second, at f/2.8, will the 40D actually focus between shots at 6.5 FPS?

I shoot lots of hockey and football and am trying to decide between the 40D and 1D Mark II. My 20D does a decent job of focus tracking, but mine is getting a little beat up and I could use a second body.

Theoretically yes, but it also depends on your lens and the quality of its USM.

Does this not depend on whether AI servo or one shot mode is selected?

xarqi wrote in post #7331277
Does this not depend on whether AI servo or one shot mode is selected?

This is correct, if you have AI Servo, it will focus. One shot will not, it focuses on your initial half-press.

GSansoucie wrote in post #7331469
This is correct, if you have AI Servo, it will focus. One shot will not, it focuses on your initial half-press.

Points taken and rephrased.

Shooting under the same conditions mentioned above, will I get 6.5 photos per second using AI Servo - preferably all of which are in tack sharp focus while using a 300 2.8 (the USM one of course).

HuskiesD1 wrote in post #7331988
Points taken and rephrased.

Shooting under the same conditions mentioned above, will I get 6.5 photos per second using AI Servo - preferably all of which are in tack sharp focus while using a 300 2.8 (the USM one of course).

You need to have it in Continuous (HIGH) drive mode to enable it for 6.5 frames per second. Furthermore, you can't have too many post-processing features on (such as noise reduction).

The 40D is supposedly the best focusing of the xxD series [with the 50D close or the same]

So I'd say it should be OK but if you're really thinking about such things, why not get a used 1D Mark II or 1D Mark IIn, the first one runs about 1200-1400 used usually..and that gives you the 45 point AF and the 8fps shooting..

The general answer is no.

Some images will be about 1/6.3 seconds apart (just like the 50D, the 40D doesn't really manage 6.5 frames/second in any case, but more like 6.3). But in some cases, focus adjustment will need somewhat more time than is available, and the frame rate will decrease. The next two images can very well be within minimum time distance again.

You'll notice this as a slightly irregular thok-thok-thok from the shutter and mirror mechanism, when you use the 40D.
It's no big deal, at least not for me.

apersson850 wrote in post #7332334
The general answer is no.

Some images will be about 1/6.3 seconds apart (just like the 50D, the 40D doesn't really manage 6.5 frames/second in any case, but more like 6.3). But in some cases, focus adjustment will need somewhat more time than is available, and the frame rate will decrease. The next two images can very well be within minimum time distance again.

You'll notice this as a slightly irregular thok-thok-thok from the shutter and mirror mechanism, when you use the 40D.
It's no big deal, at least not for me.

In AI Servo the shutter will fire even if focus has not been acheived, so the failure of the AF to keep up with the action should not affect the frame rate, resulting rather in OOF frames.