Finishing parts by painting, anodization, silvering or adding appropriate inscriptions is the next stage of production.
Every part which needs to me marked in any way is manually put into a machine which paints it. So are processed not only tubes but also transparent plastic parts with distance scales or buttons of cameras, like the one shown below with an inscription AEL. After adding appropriate marking the quality of paint is checked – a very painstaking process.
Metal parts are anodized, silvered, or painted, depending on what they are made of. Brass is silvered and aluminum is given a black anodized surface finish. Every part has to be put in a special scaffolding which is immersed in reagents. As a result of planned chemical reactions you get, after a time, a piece of metal in a desired colourful finishing.
Some parts like e.g. diaphragm blades are sprayed and then dried in special machines. Some tubes are painted as well – their outside is covered by shiny coating and inside they are matt so the lens is property blackened. It is supposed to damp down inner reflections.
