Front Projection Height Calculator
This handy calculator helps you determine what height to put your projectors at so that they still have enough lens shift to fill the screen, but are not covering part of your image. Added bonus: you can also use it to calculate heights for anything hanging in front of the screen to make sure they don't block the view.

Download for Excel
Download for Open Office

Camera Field of View Calculator
This calculator tells you the field of view for your widest and tightest shots based on your camera sensor and your lens. It even has an option to add an extender, and tells you the light loss the extender will cause!

Download for Excel