Shutter Speed via Computer?

[thehitmen]

Is it possible to control your camera shutter via USB for mac or pc?

Can this be done for pentax and Canon...

 

[admirable]

It can be done via the Canon software that comes with the camera.

 

[gingerweasel]

Capture NX from Nikon which is a little expensive or http://www.diyphotobits.com/download-diyphotobitscom-camera-control/ which is free but less polished.

I've used both in the house with my laptop to save on the purchase of a remote shutter release and they work fine.