OBSERVATION AND IDEAL
Projector help to communicate by enlarging image or video on your computer to be wide enough on a screen or white wall in a room where large number of people can see it. The whole idea of a projector is to convert a small image into a much larger one so that people can see it well.
Like camera every projector has zoom and focus key these keys help to set projector to become more brighter and clear. In a big house where there great number of people it is recommended to use big size screen 96' inches in case of that the projector will move little bit far from the screen in order to get more accurate zoom size of the screen.
Like a torch light it is quite obvious that the more closer projector rays is to the screen it become smaller and the more farther projector rays is from the screen it become larger. The projector zoom key helps but it has some extent limit level where it will stop and depends on types the projector