The Pentax MG was a product of Asahi Optical Co later called Pentax Corporation, introduced in 1981 and produced until 1984. It was a replacement of the MV and MV1 cameras as entry level 35mm semi-automatic camera. The Pentax MG was a manual focus, aperture priority camera, with no manual settings of speeds. The Pentax MG had an electronic focal plane shutter from 1s to 1/1000, synchronized at 1/100. The shutter curtains were metal and had a vertical movement. However, if the batteries fail the camera still operated at 1/100s or B, thus the selector around the release button had three positions: Auto, 100X (1/100, X sync) and B.