The Petri ES Auto is a mid-1970s rangefinder camera with automatic exposure control. In "A" mode the shutter speed and aperture are controlled electronically by a CdS meter. The CdS window is within the filter thread ring in the front of the lens barrel. Out of "A" mode speed is set to a fixed value but aperture can be selected manually. The reverse Galilean viewfinder shows a bright frame, a LED signal and the superimposed coupled rangefinder. The camera has a fast film wind lever in the back and a hot shoe on top. It was available in a variant with Petri 1:2.7 f=38 lens and another with fast Petri 1:1.7 f=40mm lens, Seiko ESF shutter and mechanical self-timer. This camera was also sold by the American K-Mart chain as the Focal ES Auto.