Projector Throw Distance Calculator
BenQ SP820 Projector
1024x768 DLP, 4,000 lumens, 2,000:1 contrast, 1.15:1 zoom, 8.2 lbsAdd to Compare List Projector Details
Why you need a Throw Distance Calculator?
A projection calculator is used to calculate a screen size when a projector is a specific distance away from the screen. As you move a projector away from the screen or wall, the image will get bigger, and as you push the projector closer to the screen or wall the image will be smaller. To properly fit your image onto a screen you need a projection calculator tool or throw chart to tell you the image size dimensions at the corresponding throw distance.
Calculating an Image Size when you know the THROW DISTANCE
To determine the Image Size (screen size) enter a distance measurement number in the Throw Distance value box and hit the Enter key on your keyboard, or slide the Throw Distance slider back and forth until you find a number in the value box that represents the distance between the lens of the projector and the surface of the screen. On the graphical representation of a screen in the middle of the calculator, you will see dimension lines that will tell you the height, width, and diagonal measurements of your image.
Calculating a Throw Distance when you know the IMAGE SIZE
To determine the Throw Distance for where you should place your projector in the room, enter an image diagonal measurement number in the Image Size value box and hit the Enter key on your keyboard, or slide the Image Size slider back and forth until you find a number in the value box that represents the diagonal distance between the top right corner of your image (screen) and the bottom left corner of your image (screen). On the graphical representation of a projector in the middle of the calculator, you will see dimension lines that will tell you the Throw Distance measurement between the front of the projector lens and the surface of your wall or screen.
Using the Zoom Range Slider
If your selected projector has a Zoom Lens then the projector's Throw Distance or Image Size can be finely adjusted by moving the Zoom Lens ring on your projector. The Zoom Range slider in the calculator will help you calculate the changes made by a Zoom Lens.
Using the blue padlock icons next to the Throw Distance value or Image Size value you can have the Zoom Range slider only affect one of the two controls. If you press the blue padlock icon next to the Throw Distance value so that the icon shows a Lock symbol, then moving the Zoom Slider will only adjust the Image Size bigger or smaller as would be visually represented if you turned the Zoom Lens ring on your projector's zoom lens to make the image bigger or smaller. If you click the padlock next to the Image Size value so that the icon shows a Lock symbol, then moving the Zoom Slider will only adjust the Throw Distance position of the projector in your room. The position of the projector in your room changes because you will need to move the projector closer or further away from the screen to maintain the same image size to match your screen when turning the zoom lens ring.