Projector Lenses

Projector Lens

When thinking in terms of projector lenses there are two factors that determine what type of lens will work best for the projector, and they are magnification and throw. Projector lenses come in three distinctive variations: singlet, doublet, and triplet. Each type of lens represents an upgrade in the quality, which directly relates to the image sharpness and focal length. Singlet is the most basic type of lens, and therefore is the cheapest. The price of the projector will vary depending upon the type of lens that is used.

Overhead Projector Lens

Overhead projectors differ slightly when it comes to lens use. The location of the lens on an overhead projector will depend on what type of overhead projector is being used. There are two types of overhead projectors: transmissive and reflective. In a transmissive overhead the lens is located in the head of machine and the light is projected upwards from the stage into the head of the projector outwards onto the screen. In a reflective projector the lens is located in the base of projector and the light source is generated from the head down onto a reflective stage, which then passes through the lens. In overhead projectors that have LCD screens, there is an additional lens called the Fresnel lens, which is a grooved plastic sheet that is light weight and has a short focal distance, and it serves the same purpose as traditional lenses.

Lens Caps

Lens caps are a crucial accessory for projectors as they help to protect your investment. The cap should be placed on the projector lens whenever it is not in use in order to protect it from collecting dust and dirt, becoming scratched and potential breakage. There are a several kinds of lens caps to choose from such as metal, hard and soft plastic, or rubber. Projector lens caps can be attached by either snapping them into place, or sliding them onto the lens. Some caps come with a spring in them that prevent the cap from accidentally falling off. Lens caps are a wise investment as they are cheap and will save you the money from having to replace a damaged lens, which can be much more expensive depending upon the type of lens the projector utilizes