Meet the Canon Canonflex. Introduced in 1959, the same year as the vaunted Nikon F, the Canonflex was quickly overshadowed by its competition. Discontinued after only about five months of production the Canonflex is much less thought of compared to the now famous Nikon F.
And yet, the Canonflex is a solid and well-built camera. It was Canon's first SLR and is slightly bigger than the Nikon F, surprisingly. It also introduced Canon's breech-lock lens mount and while it is possible to interchange Canonflex lenses with later Canon FL/FD lenses, our research suggests that this is not recommended and may result in damage to the camera and/or lens. ⠀
Other interesting features of the Canonflex include a well-designed interchangeable prism (you could get a waist level finder for this guy) as well as the bottom-mounted, left-handed advance lever that Canon boasted would allow a photographer to fire up to three frames a second, faster than the typical top-mounted advance levers.
We decided to test this "2-3 frames per second" assertion and found ourselves taken by this feature. It feels very similar to the rapid advance levers one can find on the bottoms of certain Canon and Leica rangefinders.