FD 50mm f1.4 - Silver or Black? What's the difference?

I'm looking to get a Canon FD 50mm f1.4 but I've seen two versions - One with a silver bottom and one all black. What's the difference?

Thanks!

It could be simply an age difference as to why some have the siver aperture ring and some have the black aperture ring. I know the one's I've seen with the silver aperture ring have been listed as S.S.C. (super spectral coating).

I'm curious though, why not go for a 55mm f/1.2?
http://www.ebay.com …enses&hash=item​19d1d35814

You aren't planning on using it on the 7D are you?

tkbslc wrote in post #14627203
You aren't planning on using it on the 7D are you?

The 1.2s can be adapted.......http://www.ebay.com …enses&hash=item​2a1bd3d3d0

tkbslc wrote in post #14627203
You aren't planning on using it on the 7D are you?

lol of course not, I purchased an A-1

pxchoi wrote in post #14627239
lol of course not, I purchased an A-1

Just making sure!

It's not an aperture ring as someone suggested, but the locking ring for the mount that you see on the older lenses. When mounting new FD lenses on the body you lined up the red dot and turned the whole lens. On the older lenses you twisted the ring to lock the lens on the body. Regarding optical differences I don't know I'm afraid.

I hope this helps?

I didn´t make a 1:1 comparisson, but from my feeling the new FD = nFD lenses (not silver) have a more modern image. Less "glowing" for example.
The older FD SSC lenses with silver mount ring have more metal, for example the black aperture ring is made of metal. At the newFD lenses it is made out of plastics.

I have tilt converted a FD SSC 50mm f/1.4. I like it, but I would reccomend the use of a hood (as long as you want no flares eg in the image).
The old FD S.S.C. 800/5.6 has purple fringing problems, never heard such from the new FD counterpart with "L" designation (there is no "L" on SSC lenses, this designation was introduced later with nFd lenses)