The ColorMunki will need to be on a flat surface that is a distance smaller than 1.5 times the height of the projector screen. If this is an issue you can try to move it closer and see if the device then begings to pick up the screen. The software will have you go through the alignment process and during this time if the screen is not detected moving the device closer or further away from the projector screen can assist with this. Below you will find instructions on setting this up for both Mac and PC.
Mac OS X
Mac OS X independently sets and tracks profiles for both your laptop display and your projector. Mac OS X sees the laptop and projector as two separate displays. When profiling the projector you should set:
System Preferences > Displays > Arrangement > check Mirror Displays to mirror the laptop
and then proceed with "Profile My Display". If you wish to also profile the laptop display (with projector still attached), disable mirroring. If you forget to disable mirroring you may notice that the ColorMunki application window disappears as soon as you choose the option to profile the laptop display. To recall the application window, go to System Preferences and disable mirroring.
Windows sees the laptop and projector as a single display. ColorMunki will be shown on both the laptop display and the projector simultaneously. Once the profile has been built, it will be set as the default profile for both the laptop display and the projector. When you have finished using the projector you will need to disconnect the projector and re-profile your laptop display.