Digital Rebel Hack #2 - Full time AI Servo

The Digital Rebel is a great camera, but has a number of limitations that can be really annoying in certain circumstances. One of those limitations is a real pain for sports photography and that's the restriction of AI Servo to Sports mode only. AI Servo is basically continuos focus so that you can track a moving subject. In all modes other then sports mode the Rebel uses what Canon calls AI Focus. In this mode it's supposed to detect subject movement and then switch automatically from single shot to AI Servo continuos focus. Well ... that's what it's supposed to do anyway, in reality the whole thing is just really unpredictable and doesn't work right. For sports when you need more then the ISO 400 provided by sports mode, this is a killer as you have no control over how the camera focuses. There is however, a way you can get full time AI Servo in modes other then sports. This is definitely a hack and I'll describe the many problems with it later, but it's also handy if you really need it.

What you need is a 3/32" mono plug. As far as I know it has to be mono. At Radio Shack this is part number 274-289 and it's $2.99 for a package of two. I took the plugs, removed the outer shell, broke off one of the leads and then used a metal loop from a set of keys to secure it to the neck strap on the camera. Here's what it looks like.

So what you do with this thing is plug it into the remote switch socket on the side of the Rebel like so.

When you do this the Rebel then thinks you've half pressed the shutter release. To actually take a picture you still have to press the shutter button, but the half press will stay in effect after each shot. What that means is that if you can get the camera to go into AI Servo, it will then stay in AI Servo as long as the plug is connected. So you can take multiple shots without having to pray the camera will switch to AI Servo on each one. So this is helpful, but here's the downsides.

• Getting the camera to actually go into AI Servo can be a real pain. There are various tricks that people use, waving your hand in front of the lens, focusing on a subject and then zooming in on it and a few others, but for me it's always a pain to get it to switch.
• Since the camera thinks you're half pressing the button, you can't review the pictures without pulling the plug out.
• The camera will be focusing all the time so this will drain the battery faster.
• It probably puts more strain on the autofocus motor.
• You have to be careful that you don't short the connections on the plug. This is why I broke off one of the connectors. It's probably a good idea to add electrical tape too.
• Who knows what other unintended things might happen.

Like I said, this is a hack. It works, but it's still a real pain and I'm just posting it for information. Use at your own risk, if it breaks your camera I'm not responsible. :-)

Note: I did not come up with this, I learned about it though the Digital Photography Review forums.

Posted by Kimbro Staken