I tried using a Motorola headset, bought from pasar malam. You need to cut the wire somewhere between the button and the earpiece before it would work. But somehow, the response is a bit weird, and I need to press a few times before it works.
Tried using a Nokia headset too. The moment I plug it in, it started taking photos automatically, photo after photo, like there's no tomorrow! Then I cut off the wire, but it no longer works...
i bought 2 hand free ear piece, not nokia brand but its meant for nokia phone. only 1 usable. dun know y. the construction is the same, but dun know y only 1 works. any way i took away the ear phone and solder the wire of the earphone to the switch and presto!! finished... haha.
but be warned that warranty will be void if ever canon found out that u spoiled the cam using modified/3rd party shutter release device.