I have a laser pointer and a "high end" sports led headlamp as focus aids for my view camera when focusing in dim conditions. The headlamp doubles as safety equipment when I'm out in the field, and a modern sports led headlamp can be both lightweight and powerful. Actually the headlamp is usually good enough so I rarely use the laser pointer, haven't yet bothered to get a clamp for it. If the lamp is bright enough it's usually easier to focus as you lit up an object and some surroundings and get something more "3D" to focus on than just a point.