The optical black finish on the SF-24 microphone is actually a sophisticated surface treatment designed to be non-reflective. The purpose of the optical black finish and its properties are to make the microphone appear less conspicuous, especially when used with high intensity lighting or within a camera shot. The finish requires a certain amount of maintenance to retain a smooth, even appearance and to maintain its unique optical qualities.
The metal components of the microphone’s case are comprised of a low carbon steel alloy. The outer surface is treated with a special process that is mainly responsible for the microphone’s unique optical properties. The actual finish consists of black chrome oxide deposited over a nickel substrate. Together, this process creates a finish that minimizes the reflective nature of the metal surface. To protect this finish, a small amount of oil is worked into the finish at the factory. However, physically handling the microphone and absorbent materials (like the foam padding of the microphone case), as well as any cloth will draw out some of this oil due to “wicking” action. This may give the microphone an uneven appearance as the oils are drawn out of the microscopic surface layer. To renew the appearance of the microphone simply “massage” it gently with a lint free cloth treated with a small amount of light machine oil or WD-40 applied to the cloth (not to the microphone!) will restore the microphone to “like new” appearance. Be very careful whenever working around the transducers to avoid contamination of the ribbon elements.
Age, handling, and naturally occurring atmospheric conditions will also cause physical changes in the appearance of the finish due to oxidation. This patina is quite normal and occurs slowly over time and is not considered an imperfection in the plating process. If you have any questions regarding the finish or care of this microphone please contact customer service at Royer Labs (818) 847-0121.