thoughts:<div dir="auto">i suppose you could also make a transmissive lens, the calculations may likely be based on the speed of the radiation through the material,</div><div dir="auto">what cameras do is is change the distance between lenses rather than shape them; this could be done with two mirrors facing each other, the larger likely with a hole in it</div><div dir="auto"><br></div><div dir="auto">i wonder if you could make a cheap receiver array by wiring many tiny antenna to transistors or such to multiplex among them</div>