What is Err 99 on my digital EOS camera?
This error condition is analogous to the bC error with film cameras. It s most likely caused by using an incompatible lens or dirty lens contacts. Try a different lens and see if the camera works normally. Many older Sigma lenses in particular do not work with digital EOS cameras. Try also lightly cleaning the lens and camera metal contacts – this frequently clears up the condition. Sometimes rubbing the contacts with an immaculately clean pencil eraser (rubber) can do the trick, but be extremely careful not to let any crumbs or dust fall into the lens or camera. If you have a Canon lens which generates this error and cleaning does nothing then you may need to send it back to Canon for servicing. It s possible the lens mount needs some adjusting if the lens contacts don t reliably touch those on the camera body.
