Digital Zoom
 

I know it's preferential to set your menu so that your camera only uses optical zoom, but in the event you wanted to sometimes zoom up to 15 or 18 times so you set the camera to 24 times, I assume you still have optical zoom quality up to 12 times (in the case of the GS400), or does the 24 times digital setting mean that you have reset your zoom to digital mode, even for 2 or 4 times zoom?

It's as you thought -- the "digital zoom" only kicks in when you reach the limit of optical zoom.

Thank you Brian.