Originally Posted by
CarlD
A laser level MUST be level at its source. If it's even a fraction of a degree off, that will multiply into a noticeable discrepancy. So lots of time is spent setting it up. The, the laser beam breaks up over distance--it shouldn't but I found mind did. The dot would be tiny at 2', but 1/4" across at 30' (roughly).
Another thing about lasers: the pictures always show a line...that's false. The laser is INVISIBLE in the air until it touches something You don't see a line, you see a dot.
OTOH, a water level doesn't have that problem. You can have a 50' tube to lay out a 40' pool, and it will be perfectly level at both ends--it's simply the nature of the beast. It may be difficult and require two people working slowly and carefully, but you won't get an increasing deviation as you move further away...(unless, like Chem_Geek, you start analyzing the physics of Gravity in terms of Einstein's Theory of Relativity! :rolleyes: ).
A water level is also cheap...just clear plastic tubing.
You have to get a fairly expensive laser level to be as accurate. Saying that, once the laser is set up properly, it's much easier...But keep checking it!