An image forming apparatus includes an image forming unit and a surface reflection detector. The image forming unit includes an image forming station to form a detection sample image and a toner image on a recording medium, a controller to set a detection sample image output mode to output the detection sample image, and a fixing device to fix the detection sample image and the toner image on the recording medium. The surface reflection detector is connected to the controller to detect reflection characteristics of a surface of the recording medium and includes a projector to project parallel light against a target and an angular distribution detector to detect an angular distribution of light reflected from the recording medium and the detection sample image. Based on the detection result, imaging conditions are adjusted and an output image is formed.