How to Choose a Projector Lens

Whether or not you own your own projector or choose to rent a projector just when you need one, you might not be aware that different lenses can create different overall effects with your projector, suitable for various types of occasions.


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    Understand How the Lens Works. A lens (derived from the Latin word for "lentil") is a transparent piece of glass with one or two curved surfaces. A lens uses refraction to bend rays of light as they pass through the lens. This refraction is what causes images to appear larger or smaller than they truly are.
  2. Image titled Choose a Projector Lens Step 2
    Consider Context. What is the environment like? It is broad and spacious, or close quarters? Will you be able to position the projector directly in front of the screen, or will you need to put it at an angle?
  3. Image titled Choose a Projector Lens Step 3
    Evaluate Cost. The more lenses you choose, the greater your investment. Can you rent a lens to try it out? How often will you need a particular kind of lens? What kind of maintenance, upkeep and storage are required for additional lenses?


  • Zoom Lens. The term “zoom lens” refers to a mechanical assembly of parts that allows the focal length of an image to be varied. This is in contrast to a “fixed focal length” lens, which must be positioned in an exact spot in order to project images that appear in focus.
  • A parfocal lens is a type of zoom lens that maintains image focus while the focal length changes.
  • In a rental projector, the lens is what focuses the images as it is projected onto the screen.
  • Auto-Focus Lens. The specific process used by an auto focus (AF) projector system varies somewhat from model to model, but essentially, “through the lens” autofocusing systems have sensors in place that detect certain parameters and allow the projector to autocorrect for distance, ambient light, and depth of field.
  • Nearly all rental projectors are equipped with zoom lenses, which allows you to change the angle of view and to reposition the projector while still remaining able to project a fully clear and focused image.
  • Short-Throw Lens. A short-throw lens simply refers to a lens that allows you to project large images in close or tight spaces, without blinding the presenter with bright light from the projector. These are especially useful in small conference rooms, classrooms, living rooms, and small home theaters.
  • Long-Throw Lens. A long-throw lens is more suitable for a larger facility, such as a convention hall, church, or college campus lecture hall. The long-throw lens offers greater reach without distortion, which means you can position the projector toward the back of the room, without having to create an obstacle midway across the room. Often, these types of lenses are externally mounted in front of the normal lens. These kinds of lenses are ideal for very large spaces with limited ability to change the layout of the room.

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Categories: Media | Video