The projection apparatus is used for a measurement system and projects a projection light onto an object. An image capturing apparatus performs, through an imaging optical system, image capturing of the object onto which the projection light is projected. The projection apparatus includes a projection optical system satisfying a condition of |EXP0−EXP1|/BL≦0.0015. EXP0 represents an exit pupil position of the projection optical system, EXP1 represents an actual exit pupil position of the projection optical system for a light ray of a maximum field angle in a measurable range for the object through the imaging optical system, and BL represents a base length between the projection optical system and the imaging optical system.