Using a Canon FD/FL/Canonflex to Pentax 42mm "P" Adapter
If you have an old canon camera tbat uses the Canon FD, FL or Canonflex mount, then you might struggle to find suitable lenses. One alternative is to use lens adapters. These lens adapters can make it possible to fit a wide range of different lenses onto your canon camera body, including 42mm Pentax lenses. These are still fairly difficult to find, but there are more of them available.
The Pentax 42mm lenses are all manual focus, which gives you a lot of control over what your camera is focused on. These adapters allow you to use the lens as if you had it on a Pentax camera. Using the adapters is very simple, but you still need to follow a few simple instructions.
Step 1: Installing the Adapter
The adapter is very thin and has two rings on either side. The female thread will be for the Pentax 42 mm lens and the male side will fit into your camera. Screw the lens carefully into the adapter, being careful not to cross the threads. Also avoid over tightening by stopping as soon as the lens is locked in position.
Step 2: Using the Lens
With the adapter installed, the whole assembly can then be attached to your camera in seconds. This makes it as simple as using an original FD mount lens. To remove it, simply twist anti-clockwise and then store safely.