Imagine your Canon DSLR at the top of a 10 foot pole, end of a 12 foot crane, or any place where starting and stopping video would be inconvenient. Of all the Canon DSLR cameras available (right now), the only way to start and stop video mode remotely is through Infrared. Infrared sucks, requires line of sight, and the signal gets lost outdoors pretty quick. Keep in mind that we're talking about 'video mode' which is handled only by infrared. The problem is that Canon chose to use a separate button specifically for 'Video Mode', and the normal Shutter is only for still images. There are plenty of wireless remotes for the 'Shutter', but the Video mode is activated only through Infrared.
If you've had this problem, Justin writes in and shares his DIY wireless-trigger-to-infrared remote. Using a wireless shutter remote for Photography, he hacks it in to a cheap infrared remote with S2 function (required for video mode). In the end you'll still need the actual infrared remote placed somewhere in front of the camera, but the signal from operator to camera is truly wireless which can work through walls and has no limitations with line of sight. Makes you wonder about the Zoom H4n remote... More information on the build over at Instructables (here). [Thanks Justin]
For this project, you'll need the infrared remote to initiate video with the S2 button. Found below (click here).
Wireless Shutter Release Remote for Canon EOS
I've used many of these wireless shutter remotes. The 5D & 7D have a different pin style. The one that is compatible with the 550D (T2i) has the right mini jack connection. These wireless triggers are fairly generic and the same connection works on the Canon G12, Canon 60D, Canon T3i, etc. You can find them cheapest via eBay (click here)
Wireless Shutter Remote Receiver Transmitter
BTW they fixed all this with the new 1Dx camera. Now it's all done by the shutter button which means every basic wireless trigger will now work to start/stop video mode. Of course, thats about $7,000 dollars worth of camera. I think this DIY build is a bit cheaper.
