A double concave lens has negative focal length, thereby causing collimated incident light to diverge. Double concave lens has equal radius of curvature on both side of lens. They are generally used ...

In the late eighties, single to double concaves were becoming increasingly popular. And with the changing of the competitive guard around 1990, board design took an incremental jump. Boards got ...

The double convex lens/mirror is symmetrical across both its horizontal and vertical axis. Each of the lens's two faces can be thought of as originally being part of a sphere. The fact that a double ...