It seems like it should be easy to use two lenses to 1: focus light into a small point then 2: use a stronger lens past the focal point to keep the beams fairly parallel. Experimentally, I have not been able to achieve these results. I have an LED flashlight which can project a fairly tight beam with high culmination. (shadows from objects in the beam are crisp at a considerable distance. I place a lens in front of it with a focal length of 10cm and then another lens with a focal length of 1cm, 1cm behind the pinpoint of light. I would expect to be able to keep the beam of light fairly culminated but in a much tighter compressed beam. However my results are very diffuse, and when adjusted to project an actual image, the image size is larger than the original. I'm just curious if it is possible to compress sunlight into a pinpoint, and then keep it pinpoint size by using a concave lens to focus the beam at infinity. I know sunlight isn't perfectly parallel, but it seems fairly parallel as shadows preserve their crispness for many meters. I would think you could make a psuedo-laser "deathray" capable of igniting things for at least 30 feet?