How to use 17mm lens in stop down mode

OK, my bayonet-mount 17mm differs from the other Canon FD lenses I've got - I

have only 4 - with its stop down lever that does not click into place at the end

of its travel. Any good reason why the lens was built this way? I did some

research and it seems that I need a little plastic gizmo that snaps onto that

lever so that the lens aperture will close down when I turn the aperture ring.

This device is the Canon manual diaphragm adapter. Is all this right, and is

that all I'll need? Any tips or words of caution? I'm trying to see if I can use

this lens on a screw mount camera.

After further research, I've found out that all lenses with the new FD mount need that little adapter, except the macro lenses. The only other bayonet lens I have is the 50mm macro, and it has a locking lever. Hmm, another tiny little gadget to lose.

L. M., hi. Out of curiosity, why do you want to put your aperture on manual operation? Are you using the 17 on a Leica screw mount camera or something?

 

I bought the manual diaphragm adapter in about 1980, in order to use my 28/2.8 FDn reversed for macro. I remember being quite pissed that it cost about five bucks, which seemed a princely sum for a little bit of plastic.

 

It's not a common accessory, and you may have a bit of trouble finding one. They show up on the auction site occasionally. If you're handy, you could probably make one.

Dave, yes, I wish to use this lens on a 39mm screw mount. I think it's a great lens and incredibly low-priced compared to Leitz or Zeiss glass in the sub-20mm range. It's for a cheap Bessa L body :). I've read about jamming a piece of plastic in there, but I would be concerned about that falling out and damaging the camera or, much worse, the lens. I was able to obtain one of those adapters from the used department at B&H; yes, it was $5.