High Speed Video of 5D Shutter Firing
 

This is a high speed video of a 5D (Mark I) photo shutter firing:

SLR shutter tests

The difference between shooting timelapse in Live View and normal is clear. By shooting in Live View, the mirror doesn't move, but the shutter does. That's one less thing to vibrate and one less thing to wear out.

Some are concerned that timelapse in Live View could overheat the sensor. Because the shutter is dark, it will pick up heat and could transfer some of it to the sensor. I think the solution is to shoot long exposures (something near 50% of the timelapse interval), given that it requires an ND filter and/or small aperture that will help keep things cool inside.

Note that the mechanical shutter and mirror stay open 100% of the time when shooting video. Don't film the sun with no ND and a large aperture!

Don't the silent shooting modes come into play when shooting stills in live view? Not sure that would play into this or not, but I think the behavior you describe is dependent on a specific silent shooting mode? Mode 1?

Thanks Bill,

I'll look into the silent shooting modes. I'd like to shoot timelapse without wearing out my shutter.