Canon 7D and Birds in Flight

Canon 7D, EF600mmF4 IS, 1/800 @ F4

I'm just back from a photography expedition to Utah to photograph wintering bald eagles. The eagles were quite scarce this year but I did manage to get a few good images. The weather was, for the most part poor and challenging for the Autofocus. We had snow, fog, and gloomy light most of the time when eagles were present. In the photo above I had no problem locking on the landing eagle. Having shoot nearly 2000 frames of action I think I now have a good feel of how the camera works on birds in flight. Overall I'm very impressed with the AF on the 7D. Initial acquisition is very fast. I would say it's faster than my 1Dmk2 but not quite as fast as the 1Dmk3 was although very close. The AI Servo seems to track very well and doesn't lose focus lock easily. I have custom function group III-1 set to slow. This doesn't slow the focusing of the camera down at all but prevents it from jumping quickly to another subject of object when tracking.

Canon Eos 7D, EF600mmF4IS, ISO 400, 1/2500 @ F4

This image of the bald eagle flying in heavy snow is a nightmare for most AF systems. I was able to lock on and track well most of the time with about 70% of the images in perfect focus. I was using single point AF without expansion to minimize my chances of focusing on snowflakes. I found if I didn't lock on the eagle right away bumping my AF button would quickly get my focus back on the eagle.

Canon Eos 7D, EF600mmF4IS, ISO 400, 1/500 @ F4

This image of the gull in the fog is also a very difficult target for the AF system. The lack of contrast challenges the ability of the AF to lock on and hold the subject. Here I used single AF point with expansion. The results were very good. The camera locked on and tracked the gulls with little trouble. I had trouble with previous Eos cameras in this situation.

Canon Eos 7D, EF600mmF4IS, ISO 400, 1/3200 @ F4

Again this close flyby of a male harrier in snowy conditions is very challenging. Photographing in the snow I manually choose a single focus point without expansion for the best results. Choosing the focus point manually with the multi controller (joy stick) is quick and easy and with practice will become second nature.

Canon Eos 7D, EF500mmF4IS, ISO 400, 1/1250 @ F4

I captured this image of a female harrier in the warm late afternoon light. Here I had the camera set in 19 point AF auto selection. The camera can utilize all 19 focus points to track and keep your subject in focus as it moves through your frame. I was amazed at how well this worked on the 7D. Much better than the 1d2 or 40d/50d. With relatively smooth or even somewhat busy backgrounds it was superb. The 7d displays in the viewfinder what focus points are currently focusing as you track your subject. You must first acquire focus with the center focus point for this to work properly. I'm now very confident that this fine camera can deliver professional results I require at all times....