A screen has a width of 90 inches and the necessary distance from the projector is 180 inches. What is the lens ratio?

To calculate the lens ratio, you need to understand how it relates to the width of the image produced by the projector and the distance between the projector and the screen.

The lens ratio, often referred to as the throw ratio, is determined by dividing the distance from the projector to the screen by the width of the screen. In this case, you have the distance from the projector as 180 inches and the width of the screen as 90 inches.

When you perform the calculation:

Distance from projector to screen (180 inches) ÷ Width of screen (90 inches) = 2.

This indicates that for every 1 unit of width, the projector must be 2 units away. Therefore, the lens ratio is expressed as 2:1.

This calculation allows for understanding how far back the projector must be placed for optimal viewing, based on the width of the screen. The lens ratio provides essential information for setting up the projector in relation to the screen size, ensuring that the image projected fits well without distortion or loss of quality.