A correction method for an image forming apparatus including a light source including light emitting points, a photosensitive member configured to rotate in a first direction, and a deflecting unit configured to deflect light beams emitted from the light source in a second direction orthogonal to the first direction, the correction method includes: a first correction step of correcting sparseness and denseness of density in the first direction by moving a predetermined pixel in the first direction, and causing a pixel value of the predetermined pixel to be output or not to be output in accordance with movement of the predetermined pixel; and a second correction step of correcting the pixel value of the predetermined pixel by moving the pixel value of the predetermined pixel in the second direction so that a pixel value is caused to be output or not to be output with a plurality of continuous pixels.