Projection problem

Question

I use Keynote for business presentations and when I use a projector with my MacBook, the image on the projection screen is quite dark. This happens regardless of the projector. So, for instance, if I'm one of a number of presenters and we take it in turns to plug and unplug to the projector (the others are usually Windows laptops), my 'slides' show much darker.
They look fine on my display and although it's not been calibrated, it does show a test image correctly.
I'm using the VGA output.
Any ideas?

Answer 1

Yes, the gamma is adjusted on the MacBook. It needs to be done for each projector because OS X maintains a record of every display that gets attached to the MacBook according to the display's unique product ID. That's why you only have to make the adjustment once per device (display) because OS X will keep a history showing that you want certain settings related to the specific product ID.
It won't affect the built-in display because, like all the other displays, the built-in display is also tracked by its unique ID. So whatever changes that get applied to external displays will not apply to the MacBook's built-in LCD.
An example of how you do this procedure is; attach the projector, open Displays Preferences and click on the Color tab for the projector. Click on Calibrate... and then click past all the screens until you get to the one for gamma. Set gamma to 1.8 and then click past the rest of the screens. When you get to the point where you can save the file, name the file Projector.
When you attach other projectors, instead of going through that procedure again, you can just open Displays Preferences, click on the Color tab and apply the Projector color profile to the other projectors as well.