Locking Minolta SR/MC/MD Lens To Canon FL/FD/FDn Body Adapter

Minolta's manual-focus SLR lens SR bayonet mount was introduced in 1958 and continued as the compatible MC and MD mounts through 1998. In 1964, Canon introduced the FL lens mount for their SLRs and continued with the compatible FD mount through 1990. Through all that, there haven't been any adapters to mount one type on the other... until I made one in 2013 and finally, in 2023, this version that locks.

This adapter allows a Minolta SR/MC/MD lens to focus to infinity when used on a Canon FL/FD body -- or, more significantly now, on an FL/FD adapter for a digital camera such as the Sony NEX models. Thus, for example, if you have a bunch of old Minolta and Canon lenses, you can use them all with an FL/FD adapter, FD Lens Turbo, etc.  The lens mounts rotated a bit from the normal orientation in order to avoid mechanical conflicts with some FD mount stop-down levers, but that's only an issue if your lens contains internal rectangular masking, which most don't.

This adapter is fully locking on both the Minolta lens and Canon body sides using plastic structures to form springs. The spring tension is about right when printed with PLA at 100% infill; other materials might result in different spring characteristics. The adapter and locking mechanisms are somewhat fragile and certainly can be broken or forced, so use this adapter at your own risk. I'd suggest avoiding the use of very heavy lenses with this adapter.

The design is an easy print except for the spring lock for the Minolta lens. It has an unsupported span that you might need to print with supports. Also, as shown in the photo with the red marks, you'll need to free one end of the spring by using pliers to cut the print in the spot shown (it is printed connected because that helps with printing the span; in fact, I printed it without supports). There are also two indentations for mounting alignment marks, which can be filled with a dot of paint to make them more visible as I've done here.

The Minolta SR/MC/MD lens mounts normally on this adapter using the alignment dot on the flat surface. Similarly, the adapter mounts on an FL/FD body or adapter by aligning the dot on the side and then turning, however, you'll need to keep the locking pin disengaged by pushing the tab toward the dot until you have it rotated into position. Once in position, the locking pin will spring into the cut in the FL/FD mount and should hold until you again push the tab to free it up. In contrast, there is no release tab for the Minolta spring lock; you merely turn the lens to disengage after a little initial resistance, so be careful not to force it when you don't want to remove the lens.