The new Canonet series developed for compactness and lighter weight.The camera was about 20 mm narrower, 4 mm shorter, and 30 percent lighter than the previous Canonet.To make it more compact, the lens focal length was shortened to 40mm, resulting in a wider angle lens. A Speedlite (Canolite D) which did away with complicated Guide No. calculations was also introduced. The flash aperture was set automatically to suit the flash output and subject distance. This was the fully-automatic flash system called CATS (Canon Auto Tuning System) incorporated for the first time.
With this feature, picture-taking with EE was completely automatic for both night and day.
The "G" in the camera designation stood for "Grade Up" which referred to the quality improvement. The "III" indicated the third-generation Canonet series, following the original Canonet and the New Canonet.
The basic specifications were the same as the New Canonet QL17's. Checking the battery was easier with a battery check button on the side of the viewfinder eyepiece. A lamp would light when the battery was still good.
Manufactured from spring 1972 to summer 1982, it was a long-selling bestseller over 11 years. About 1.2 million units were made.
