Fotodiox adapter won't mount certain Canon FD lens

[OlyPent]

I've had other m4/3rds to FD adapters which worked.

Canon's FD lens, the 58mm f/1.2 has a raised internal ridge that hits the side of the pre-set aperture pin which is set too shallow in the m4/3 and Sony NEX to Canon FD lens adapter. The ridge, when the lens is properly seated, is 6.5mm inside the camera bayonet mount. The pin in the Fotodiox adapter is only 6mm deep, hence they impact. This will require removing the pin (remove, cut if off, etc) in order to mount the lens.

Side view of Canon lens showing raised internal ridge (black) in lens mount.





Image showing Fotodiox pin being hit by the ridge in the lens mount. (RED). Yellow shows the gap where the mount won't close.

 

[ReFoCus]

Not sure if that one has a second aperture ring at the front of the lens that controls the aperture but I have a Canon FL 50mm f1.8 that has one and had to remove the screw so it can fit into the adapter from the adapter so it can fit.

It was not until I saw the video below that I got it fit working and noticed the second aperture ring. So basically you have to preset the aperture and use the second ring to actually close the blades.

 

[OlyPent]

That's what's going to have to be done. The adapter I have will need the rod removed slightly differently, but it should fix the issue. The lens does have a 2nd aperture ring, I've seen this on old lenses before.

 

[Heritage Cameras]

With many of these FD adapters you can remove the diaphragm pin by simply unscrewing it from the outside. This leaves a hole that could cause light leaks, but the hump on the rear of the lens should cover it up.

 

[brightcolours]

With many of these FD adapters you can remove the diaphragm pin by simply unscrewing it from the outside. This leaves a hole that could cause light leaks, but the hump on the rear of the lens should cover it up.

Just close the hole with a small enough screw.

--
Dave, HCL

 

[Lightshow]

First, it's not an FD lens, it's an FL lens, yours is the FL 58/1.2, there are a few others that have this hump, the FL 35/2.5 being one off the top of my head that I can recall because I have it.

You are right that removing the pin from the adapter is the solution to letting the lens mount, you may wonder what happens with your other Canon lenses, well surprisingly, not much, FL lenses have a direct connection with the aperture ring, and does not require a pin to get full functionality, FD is a bit more complicated, Canon added some interlocks to the lens mount that need to be engaged to permit the aperture ring to effect the iris, but thankfully Canon was thinking about backward compatibility, all you have to do is push the aperture lever on the lens to the end of its slot, you should feel a click, and it will stay there, the lens will now operate like an FL lens when mounted, I have all my FD lenses set to this condition.

Now comes the bad news, nFD lenses I've tested can't do this, so for those you will need a pin to engage the aperture lever, IMO, it's easier to buy a separate adapter for nFD lenses, then all your FL and FD lenses mount the same way, and you don't need to turn the lock ring of the adapter to activate the aperture any more!

 

[OlyPent]

Not sure if that one has a second aperture ring at the front of the lens that controls the aperture but I have a Canon FL 50mm f1.8 that has one and had to remove the screw so it can fit into the adapter from the adapter so it can fit.

It was not until I saw the video below that I got it fit working and noticed the second aperture ring. So basically you have to preset the aperture and use the second ring to actually close the blades.

That was it, simple removal of the screwed-in pre-set pin in the adapter. Thank you that fixed the issue.

 

[OlyPent]

With many of these FD adapters you can remove the diaphragm pin by simply unscrewing it from the outside. This leaves a hole that could cause light leaks, but the hump on the rear of the lens should cover it up.

Just close the hole with a small enough screw.

 

[Inukim]

Heres my solution with my K&F concept adapter.

Loading…

www.dpreview.com

 

[ReFoCus]

Not sure if that one has a second aperture ring at the front of the lens that controls the aperture but I have a Canon FL 50mm f1.8 that has one and had to remove the screw so it can fit into the adapter from the adapter so it can fit.

It was not until I saw the video below that I got it fit working and noticed the second aperture ring. So basically you have to preset the aperture and use the second ring to actually close the blades.

That was it, simple removal of the screwed-in pre-set pin in the adapter. Thank you that fixed the issue.

You're welcome!