Spirit level
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A spirit level is an elementary device with a bubble trapped in a liquid, in such a way that the horizontal can be exactly established. A spirit level is very useful in many types of photography, because off-true horizons and verticals are visually distracting.
Many good tripods are fitted with integral spirit levels. Stick on spirit levels are also available, as are hot-shoe spirit levels, although not all cameras feature horizontal hot-shoes.















