An image formation apparatus has an image forming section including an optical system for forming an image corresponding to an image of an original, a potential sensor for measuring a surface potential of a photosensitive drum for forming a latent image thereon, a potential measurement circuit for calculating an average value of the surface potential, and a controller for controlling an exposure of a halogen lamp according to an output for the potential measurement circuit. The apparatus can reproduce optimal images of different types of originals including newspaper articles or the like which generally cause background fogging.