If you want your projector to show excellent, high definition images you will need to make sure it has a good, capable lens. Most multimedia projectors allow you to use assorted interchangeable lenses and conversion lenses with them. Some projectors don't include lenses with the projector. This allows you to pick and choose the lens or lenses you wish to buy. You can get various sized lenses with different apertures. Wide angle lenses, zoom lenses, short, middle and long throw lenses and ultra wide angle lenses are commonly used in multimedia projection systems.
Make sure that your lens is made to work with your model of projector. Lens caps, bags and mounting adaptors are also available. Lenses can range in price from about $150 to $6,000.