Ryan, some points in no particular order:
You can’t expect to use the same iris setting for the screen and the presenter, if they are not lit to the same brightness. You can do four things here:
Get a second camera that frames only the presenter, with the iris set for him only, then set the first camera’s exposure for just a closeup of the screen, without the presenter.
Forget showing the screen, Shoot and only expose for the presenter, then add all the slides back in post, from exported JPEGS or TIFFs from Powerpoint.
Shoot from a more head-on angle and light the presenter while adjusting the light so it doesn’t wash-out the projection screen.
Stay with the single camera for now, always expose for the speaker, let the screen get blown-out, then add the slides back in during post, but shoot the speaker 99 percent of the time, with some instant re-frames and zooms to change angle in the pauses between paragraphs, during breaths, or at the end of a logical thought.
You can always go back and add slides later, see, but what you’re there for is to record the *person* first and foremost… humans actually prefer to look at other humans, and you should mostly shoot the speaker in medium shots and facial closeups (allow for hand gestures). This body language is how we communicate, and the graphics come second. You want to put up the slide just long enough to read it and understand it, then get off it and back onto the presenter, who is telling the real story. Otherwise, you’re recording an audiobook:-)
If you change the framing on the presenter in a regular, systematized way, you will subconsicously make things easier for your audience to follow along. What I mean, for example, is:
Slide with major section title, full-screen, as the speaker starts talking about it.
Cut back to speaker in medium wide shot as le leads into his first idea or list of terms.
Cut to the slide full-screen and hear him read those aloud.
Cut back to speaker after he’s said whatever is on the screen, but now the shot is closer.
Cut back to the text screen when he finishes the thought and the new screen has come up.
repeat.
Variations:
To break things up, or provide cover for a zoom transition, cut-away to audience footage you shot in the ten minutes before the presentation started.
Make a 2-box shot or a picture-in-picture shot of the speaker and the slide together. Don;t dwell on this too long, it is just to hep remind us which slide we were on.
When someone skims thru this presentation in fast mode, they will see a pattern that makes it easy to find a particular section, because each one starts out the same, like a book chapter, with the text screen by itself, the wide shot for the opening shot, and then more screens with medium shots. The conclusions always end on a closeup, to visually punctuate the speakers’ point.
Another thought: shooting the text of the powerpoint with a camera as it is projected on the screen, is a very backward way to capture the visual information, and it’s much lower readability and quality, compared to importing the original slide images. Unless there’s a compelling reason like the presenter plays shadow puppeteer with the projection or something, overlapping the screen, there’s little reason to shoot both together. Watch ANY of the TED Talks videos with the sound off and see how they handle graphics and how they choose to shoot the speaker.
Think about this: most formal speakers will :
Tell you what they are about to tell you,
Then Tell you the actual thing,
Then recap and summarize what they just told you.
You do not and should not be shooting the same camera angle of the guy doing each of these steps. If you do very ultra-fast zooms to change up your angles at each of these sections, and cut on a breath or a pause, using cut-aways of the slide or audience where necessary, the final edited product can look as if you shot it with a 3-camera live-switch, your audience may stay awake thru most of it, and only you and I know it was done with just one camera.