In the era of film cameras 'FED', 'Change' camera repair shops used to lubricate fotomehanizmov bone oil, as more resistant to temperature fluctuations. While the shortage and inaccessibility were commonplace. In the absence of a sale of the oil it offered to produce their own. Here's one recipe: clean of meat bones bull or cow's feet, crush them into small pieces and placed in an enamel dishes and fill with distilled water. The whole product is cooked for 5-6 hours. over low heat, without putting a large boil.
Appeared during boiling foam gradually removed. The prepared liquid broth is cooled, after which surfaced on the surface of the fat collected in separate glass bottles. Then take four well-washed bottles, glass insert them into a funnel with filter bandwidth of the paper. Gradually and carefully pour the fat one of the craters. Filtration of fat is slow and not immediate. When all the fat will be filtered in the first funnel, pour it into the second, then third and so on. Do this for as long as the fat becomes completely liquid. Cooked oil settles in for a month. After that, oil is separated from the precipitate, filtered, and only then apply the grease fotomehanizmov. The mechanisms of most modern digital cameras work without lubrication through the use of special materials.