During this time in Europe, German-made Lens-Shutter 35mm SLR cameras were at the forefront. To counter this and to respond to the European subsidiary’s desire for such a camera, the Canonex was developed. It was Canon’s first and last Lens-Shutter SLR camera.

The main features were shutter speed-priority EE with a built-in selenium exposure meter, an aperture scale and match needle in the viewfinder, and a metering and exposure window having an exposure warning zone.

With conventional Lens-Shutter SLR cameras, the light entering the camera through the eyepiece during the exposure was blocked by a blinding curtain behind the mirror. However, since the Canonex’s mirror also functioned as a blinding curtain, there was no separate blinding curtain.