Its an interesting challenge to get decent photos of a presenter whos using a screen like this.
If you use your flash and the speaker is at all close to the screen, it ends up looking mostly white. A huge white screen often makes the speaker look flat and uninteresting, or too dark with auto-exposure.
I do like to play around with screen photos like this, where the subject is actually being hit by the light and it can #1 give you a decent exposure on both the screen and the subject and #2 it can look cool 🙂
You can very quickly improve the looks of a screen.
Make a selection around a screen by using the Polygon Lasso tool (an optional tool under the normal lasso). Just click for the points to make the lines of the screen edge.
Adjust levels in your favorite way
Then from the Image Menu, choose Adjust, Hue/Saturation. Tweak the image to correct off colors and make it look more natural.
Anything you made look weird (like a hand inside the screen area), you can easily undo by using the History Brush with the history set before you made the screen selection.
(and PSThese photos arent really prepped… theyre just for example!)