Laser level line cap question

The line cap is a gizmo that fits over the laser and causes the beam to fan out into a second dimension.

The standard laser beam projects a one-dimensional beam that appears as a point when the beam is projected onto a surface. With the line cap installed, the beam becomes two-dimensional and will appear as a line when the beam is projected onto a surface.

If we start by assuming that the laser level is level, the undeviated beam should also be level. Installing a line cap will make the beam fan out to project a line onto a wall or other surface, but the projected line can be level, plumb, or somewhere in between -- depending on how the line cap is "clocked" on the laser level.

It can be a useful tool, but you need to remember that having the bubble centered in the vial does not in any way assure that the line projected onto the wall is level.

John