calculating throw distance
correct throw distance depends on the screen size and lens present—the larger the image needed, the greater the distance you must allow between the lens and screen. once you know the screen size and lens type present, you can calculate the precise throw distance you require by using the appropriate formula as found in this appendix.
throw distance is the distance between the projector front feet and the screen (figure d-1). this measurement is not necessarily parallel to the floor—i.e., the projector and screen may both be inclined.
note: if your projector is tilted up or down in relation to the screen, typical in large venues or elevated installations, throw distance still represents the smallest measurement between the screen and front feet center axes.
figure d-1 provides the recommended throw distance formulas for each of the “compact” thunder lenses. pre-calculated throw distances for the complete range of lens types and screen sizes appear in the charts and graphs on the following pages. refer to these examples to quickly determine the proper throw distance (±5%) for your installation and lens.
table d-1. throw distance formulas
make sure to use horizontal screen size in all formulas.
throw distances for compact thunder lenses
