So many times I could have used one. Everyday light duty B&D drill has one built in. It can and has been handy. But I'd like to get a decent one. Trouble is, even the ones that push say $75 (I know they can cost hundreds) have an accuracy spec I think sucks for a laser. If I recall, lasers are coherent light and are pretty darn straight. Light travels straight unless it's bent or distorted and laser light doesn't disburse in general. Also if I recall, the intensity and directness of laser light depends a lot on the mirrors generating the exit beam.
How the hell did I get off on that tangent...?
Anyway, I see accuracy of +/- like 1/2" in 100'. Saw a $35 Sears brand one today (not self leveling) that was +/- 1/2" in 30 ft. Crimus!, I can almost do better than that eyeballing.
What exactly is the "accuracy" spec?
For a self leveling one, does this mean the two endpoints at the spec distance and be off up or down by 1/2"?
How about one that is not self leveling...basically shooting a straight line. Does it mean the beam can be bowed +/- 1/2" at any point alone the line?