[Jason H. Gao] and [Li-Shiuan Peh] used an infra-red (IR) line laser and the camera on a smartphone. Their prototype cost only $49 since they used a smartphone that was on hand. The article ...

Suiting when working at long distances or under bright sunlight, this special reflective Objective film target card plate can increase the visibility of the red laser line or dot. Designed "L ...