The FL Series Lenses

The Lens is the Eye of the Machine
Canon introduced the FL Lens System in April of 1964 with the Canon FX camera. This replaced the previous Canon R mount that had been devised for the introduction of the SLR cameras. This lens design was based on the concept that the lens not turn as it was mounted on the camera so that the mating surfaces would not wear against each other and to simplify the engagement of the aperture pin on the rear surface of the lens.

On the back (to the left) of this lens you can see the “Breach Lock Ring”. On the front (to the right) you can see the silver aperture setting ring.

The single pin on the back of an FL lens is shown. Note how uncluttered the back of an FL lens looks. The locking lugs on the Breach Lock Ring are clearly visible.

This was accomplished by putting a “Breach Lock Ring” on the back of the lens that contained lugs that mated with the camera locking lugs. A pin on the lens prevented it from turning as the Breach Lock Ring was turned engaging its lugs in the lens mount. It was held in place by friction alone so it was important to snug it up but not over turn it so that it was hard to remove.

The distinguishing features of this lens, aside from the “FL” letters inscribed in the front lens ring, are the two silver rings, the Breach Lock Ring and the Aperture Selection Ring,  that are visible in the picture to the left and the single Automatic Aperture Pin protruding from the back of the lens. It is easily recognized.

The desired f/stop is selected on the Aperture Selection Ring but the lens remains wide open. When the shutter is pressed the camera body has a lever that engages the Automatic Aperture Pin and the lens shuts down to the previously selected f/stop. Then the shutter curtain is released, the exposure is made, and the lens reopens to full aperture. It happens in the blink of an eye.

This predates automatic exposure settings and so the only information communicated to the lens is that the shutter is about to fire and the lens must stop down. Thus a single pin suffices.

The neat clean appearance of the rear surface of the lens is a clear giveaway that this is an FL lens. So now you too can recognize what you are looking at when you hold an FL lens at a camera show!

FL Lenses in the Collection
Here are the FL lenses I have been able to acquire so far. It is a time consuming process to shop on Craig’s List and E-bay. And of course I am working on a budget. It would be no fun if I just went out and bought one of everything. Where would the thrill of the hunt be? I would miss the satisfaction of finding a good bargain.

I have more than you see here because it takes time and work to get them all listed.

FL 50mm f/1.8
Standard lens for the early F Series

Canon FL 19mm f/3.5

FL 19mm f/3.5
Super wide lens for the early F Series

Canon LogoThis page is not a review of this Canon equipment but rather a record of an item in my collection. I have no connection with Canon and receive no remuneration nor benefit for this listing. It is for my own use and possibly your enjoyment!.