LiveView auto off

[bart1983]

Hey guys,

I am a wedding photographer and I want to make a photo booth for my wedding guests. It includes a box, a Canon 50d and a HDMI LCD display. But when I activate the liveview to see something on the HDMI display the liveview turns off after nearly 30 minutes. The sticky HalfShutter option helps to prevent that. But after taking a photo, the shutter button must be pressed to half again to activate the sticky HalfShutter. I can not say to all the guests that they have to activate the HalfShutter after taking some photos.

Is there another way to prevent turning off the liveview automaticly?
By the way the canons option "power-off time" is set to "off".

Bart