If that is poor in your books, try self-leveling laser levels
, you can't breath at them
Ha ha I have, as I am building a house and have tried to align door frames, windows, ceilings and floors. I have about 5-6 of them and have already dropped 2-3 :-(
They need very stable mountings and a lot of patience to set them where you need to, very soft touch and hold your breath. Literally. For example I used a handsaw hanging upside down on a nail in the wall as a base for the magnetic laser level. Trying to set that assembly up is an exercise in patience. You cana see I am using 3 lasers to help align a door frame, one is on the floor, the other on a tripod and the other on the hanging handsaw blade

I have also discovered. You need to align it to within 1 degree, preferably less, *before* you unlock the pendulum, and only then let the pendulum do its magic. Because, if you are out by say one degree or more, the pendulum will still align, but not as well as when you started off at 0.5 degrees. They usually self-align from 3 degrees downwards, but I would not trust them.