Keeping camera focused when shooting video

[jla930]

How do you keep the Rebel T3i in focus when shooting video of moving objects that are moving toward or away from the camera? I understand the Nikon D5100 has continuous autofocus, but the Canon EOS Rebel T3i does not have such a feature.

[jla930]

Anyone?  Thanks.

[srwheel]

I hope you find an answer. I have a related problem with the T4i which has auto focus so part of the problem is solved if you would upgrade to that or the T5i. Unfortunately you get another issue to resolve though. The T4i is so sensitive to motion and change of focal distance that it is constantly moving the lens in and out as the object moves. There problem is two fold: a) lens movement noise is recorded. b) The captured video is very jerky as its changes focus for every movement. Very distracting. I am hoping with my own post to get some professional answers to the focusing problem.

[Richard · Accepted solution]

Hi jla930,

AI Servo AF  mode is for moving subjects when the focusing distance keeps changing. While you hold down the shutter button halfway, the subject will be focused continuously.

To access this mode, press the right arrow (AF) button, and choose "AI Servo", as shown below:

• The exposure is set at the moment the picture is taken.
• When the AF point selection is automatic, the camera first uses the center AF point to focus. During auto focusing, if the subject moves away from the center AF point, focus tracking continues as long as the subject is covered by another AF point.

[jla930]

Thank you.