Spirit level

Glossary Terms

Voigtländer Tourist with circular levels in the focusing and front rise knobs image by Geoff Harrisson (Image rights)

K W Box Reflex with a circular level image by Tony Kemplen (Image rights)

A spirit level (sometimes called a bubble level) is a simple gauge used with cameras and accessories to show whether they are correctly aligned to the horizontal. A bubble of air is trapped in a capsule of alcohol or water, and sits in the highest point of the capsule.

A typical spirit level is a tube, curved very slightly so that the highest point is in the centre when the device is aligned horizontally. There is often a pair of marks, between which the bubble sits when this is so. Such a tubular level indicates level for either pitch (front-rear tilt) or yaw (left-right tilt), so a camera is likely to have separate levels for each axis. If a device is always intended to be used level with respect to both pitch and yaw, a single circular spirit level may be provided, which can show the device is level in both axes (a circular level does not indicate yaw so well if there is intentional pitch). A circular level is often attached to the brilliant finder of better folding cameras.

Panoramic and stereo cameras often have built-in levels, at least to show yaw. Spirit levels are sold as accessories, where a camera does not have built-in levels.

Some digital cameras have electronic level gauges.