Using 100mm/2.8 USM on older EOS Body no AF

[AnselAdams4x5]

I just purchased a 100mm/2.8 USM Macro lens. Works perfectly on my 6D. It does not respond at all on my film EOS A2. I have three other EF lenses, 17-40 L, 28-135 IS and 70-300 IS. All of these other lenses work fine with my film EOS A2. Does anybody know why?

[deebatman316]

Can you please provide the full name of the lens. Canon has released 2 versions of this lens an L and Non-L version of this lens. Have you tried cleaning the contacts on the body and the lens with rubbing alcohol. DO NOT under any circumstances use a pencil eraser to clean the lens contacts. The lens will work on both bodies just fine. Does the lens even attempt to AF on the EOS A2.

[normadel]

ANY EF lens should work fully on ANY EOS body, film or digital.

Any error messages on the A2? Does the 100mm lens not focus, not let you take a picture, what...?

Could be a contact problem between lens and body.

[ebiggs1 · Accepted solution]

" Have you tried cleaning the contacts on the body and the lens with rubbing alcohol."

Unlikely to help since the other lenses work just fine. Cleaning the contacts rarely to never helps if the lenses are routinely changed. That act is generally enough to keep the gold plated contacts in order.

[ebiggs1]

Make sure the battery in the old camera is fully up to the job. If it is still the original replace it today. Also make sure the battery charger is working properly. You might try resetting it too. That is usually always the best first step when something that should work doesn't. You know the lens is good so it has to be in the camera.

[deebatman316]

That camera uses 2CR5 batteries. Not the typical rechargeable batteries we have today.

[ebiggs1]

Not the point, my  friend, the battery(s) may be under capacity.  Quote, "If it is still the original replace it today."

[deebatman316]

But why would the other lenses work fine then.

[AnselAdams4x5]

No response at all. Not L series just USM no IS. All my zooms work fine. 

[AnselAdams4x5]

All my zooms work fine on old A2. 100m works fine on 6D. Manual focus OK