These lenses allow you to resize images on the screen without moving the projector. Now began to produce projectors with a sliding lens cover – it's convenient, because the cap is not lost and does not project beyond the edges of the front panel. Moreover, the sliding cover often done with a pause function – slide the cover, you will automatically turn off the projector for a few minutes – for example, to communicate with the audience. Then, pushing the lid, you can immediately continue running. On some projectors change the focal length manually, others are equipped with motorized lenses, allowing to scale the image using the remote control. Manual control more quickly and accurately, and Motorized lens handy when they have to operate at a distance, for example, if the projector is highly fortified under the ceiling.
Some manufacturers provide the most expensive and powerful models of their projections the use of interchangeable optics: additional long-focus lenses enable the projectors used in large halls, and wide-angle lens – in a limited space, as well as the lumen behind the screen. Lamps In most modern projectors are used sverhdolgovechnye lamp with a lifetime of 2000-4000 hours, which means that even with frequent use of the projector lamp replacement required only a few years. In each projector has a lamp counter, which promptly reiterated the need to replace it. Management Tools Ease of management – a crucial measure that must be taken into consideration when choosing multimedia projector. The primary means of controlling the projector is an infrared remote control that comes with each model.