In case the optics have more issues than mentioned above which need to be resolved, we strongly advise a complete lens overhaul. The zoom and focus mechanisms have a lot of moving, sliding, and rotating going on. An aperture mechanism is still a physical, mechanical device anyway. If the aperture mechanism fails due to oily blades, your aperture control is lost and you’d be forced to shoot wide-open, with a bad outcome. There are a variety of reasons why aperture blades can get sticky, or even completely stuck, such as: oil on the aperture blades, damage to the aperture mechanism, a disconnected or worn out return spring or faulty or dirty electrical contacts. Exposing your lens to extreme temperatures can cause the grease inside your lens to separate. The oil can flow or evaporate onto the aperture blades, but it can also end up on the glass elements or other internal components of the lens. Some lenses are more prone to this than others due to their constuction or the type of lubricant which was used.
Our Camera Revival technicians will disassemble the entire lens and it’s optical groups (if necessary). Subsequently all mechanical parts, including the blades and screws, will be thoroughly examined and cleaned. This process involves the use of sometimes toxic chemicals. Why experiment with them, if we can do it for you. Broken parts will be replaced, parts will be lubricated and reassembled in the correct order following the individual specifications of the lens.
After we’ve assembled everything, we do an extensive precision alignment of various parts. Finally, we double check or even tripple check everything in our lab with the help of our extensive range of optical equipment to be sure everything works perfectly. In the end, your lens will be good as new, back to factory specs or even better.