An image forming apparatus includes a control unit configured to detect a misregistration amount and densities of the toner images by detecting first and second detection patterns. The first detection pattern includes black and color portions, and the control unit is further configured to set a light-emitting amount of a detection unit, a threshold, or a sensitivity of a detection unit so that a received light amount of diffuse reflection light from the black portion is less than the threshold and a received light amount of diffuse reflection light from the color portion exceeds the threshold, and to set the light-emitting amount or the sensitivity so that the received light amount of the diffuse reflection light from the color portion is less than an upper limit of the detection unit.