So here is an illustrated guide for the maintenance and cleaning of the Kiev 16 lenses. I'll just do this with the example of the 12mm lens. The other two lenses are very similar, and if you can do the smallest lens, you probably can do the other two as well. With all 3 lenses, the focus was extremely stiff and could only be moved with some effort. Since the lenses are relatively small and are quite close together on the turret, you only have the chance to turn the focus with your thumb and