An optical print head including a light emitting member, an optical member, a detection unit, and a correction unit. The light emitting member is elongated in a longitudinal direction with light emitting elements arranged along the longitudinal direction. The optical member is elongated in the longitudinal direction with optical elements arranged along the longitudinal direction, the optical elements collecting light emitted by the light emitting elements. The detection unit detects an index value of linear expansion difference in the longitudinal direction of the light emitting member and the optical member. The correction unit uses the index value to correct an emitted light amount for each of the light emitting elements in order to offset differences in light collection efficiency caused by the linear expansion difference.