What is "throw distance" and how does it work?
There are two projector terms that use the word throw — throw distance and throw ratio. Throw distance describes the possible range of distance between your projector and surface, while throw ratio describes what size of image the projector will create at a given distance.
Throw distance is the focal distance between your projector and your projection surface. Simply put, this measurement tells you how close the projector needs to be to your window, wall, Hollusion Projection Material, or 3DFX Form in order to create a clear image.
A projector's throw distance is usually expressed as a range. For example, the AtmosFX Digital Decorating Kit has a throw distance ranging between 3 and 20 feet. Using the zoom lens to focus, the projector can be placed anywhere from 3 to 20 feet away from the projection surface.
Projectors are usually categorized as being either "short throw" or "long throw", meaning they have a short range or a long range. Most decorators prefer short throw projectors when setting up digital decorations because the projector can be placed closer to the projection surface.
A projector’s throw can also be measured using a “throw ratio,” which describes how much a projector will magnify your video image at a specific distance. Finding out the throw ratio of a projector will help you determine if it will work well for digital decorating because short throw projectors have lower throw ratios than long throw projectors.
The smaller the throw ratio number, the larger an image the projector will produce at a short distance.
Epson published a tool which we find very helpful for understanding specific throw distances. The calculator can help you develop an idea of what throw distance will work best for you. While you are planning your decorations or shopping for projectors, it can be incredibly helpful to plug your own numbers into this calculator.