0orksecurity 10 years ago Many lenses and lens systems can be used to gather light over a wide area and focus it down to a smaller area. A fisheye camera lens, for example, gathers light from a full hemisphere and directs it into a circle smaller than the film frame so all of that is visible. A telescope gathers light from a narrow angle but over a wide area, focusing it down to increase brightness rather than to show more.If you really want all the output going "in one direction" rather than being resolved at a specific image plane or focal point, you're talking about collimation. Websearch on that term will find more info on that topic. You're not going to get perfect collimation unless you're using the incoming light to pump a laser... and even that tends to be less than perfect in practice, if I remember correctly.Websearching on "lenses" and "optics" will probably find some good introductory lessons on what lenses can and can't do.