No focusing on my subject

[fluentdesigns]

I recently decided to jump into photography when I started a small digital motocross magazine. I purchased a 40D with a f4 70-200 lense. Now my problem I had yesterday was when I was shooting the racers at the track and kept noticing that the camera would randomly focus in on the background and not the rider. I was using the action preset on the camera and letting the it auto focus. The weather was overcast but not sure if that has to do with anything. Is there something that I am doing wrong? I had a lot of wasted shots because of this. Any help would be grateful.

thank you.

[40Dude6aedyk]

May I suggest you practice with your camera on subjects that are not moving first? The camera doesn't really know what is moving and what is not moving. Why shouldn't it focus on the background if that this the main thing in the viewfinder?

I imagine that the racers pass in front of you at the same distance all the time. That means you could use manual focus and get great results. Have you tried manual focus?

So park a bike somewhere in front of a typical background. What happens when you take a picture of the bike? What happens if you move your camera a little bit so the center point is not on the bike, but just off it and on the background?

Also read your manual about AF AIServo mode.

[40Dude6aedyk]

Oh, did you notice there is a motorsports forum on this site as well?

[DDCSD]

Can you post a few examples of the shots you are unhappy with?

[DDCSD]

Oh, and welcome to POTN!!!!

[DC Fan]

...the camera would randomly focus in on the background and not the rider.

Try using the center autofocus point only?

[eigga]

Thats a big jump to go from auto settings to manual focus. Seriously, the camera he has can do a great job of auto focus if used properly.

I would highly suggest starting with AV (you need to at least learn this) and center auto focus as suggested. Letting the camera decide what to focus on will most often lead to mixed results.