Re: Lighting for presentations w/powerpoints?

There are a couple of ways to approach it. The most professional way is to, as you suggest, edit in the powerpoint content in post. Or, you could shoot with two cameras -- one on the podium and one on the powerpoint screen, and again edit in the footage later. It makes sense to give the client some options -- if they're willing to pay extra for a professional product, so be it -- if they want to cheap-out and are satisfied with an inferior product, at least you've covered yourself.

As far as lighting goes, you're dealing with two different color temperatures, as the powerpoint stuff will be daylight balanced, much like a TV monitor, and the house lighting will be incandescent. So, if you augment the house lighting with a tungsten fresnel and color balance to that, the resulting powerpoint images will look blue. So, shooting with one camera will only work if you can throw some "blue" light on your speaker (to match the powerpoint).

Alerting your client to this mismatch in color temps is a good idea in advance, so as to avoid surprises.

Also, if you do bring it supplemental lighting (and HMIs are the answer here), if you angle the key light as if it were originating from the powerpoint screen, it will sub-consciously look as though the speaker is being "lit" by the powerpoint screen. It's a nice touch.

With your DVX100, do some testing. Shooting in 24fps can be problematic if there's interlaced video in the content of the powerpoint. Shooting @ 30 frames progressive is a good alternative.