1. Remove the focus lens from the holder by gently rotating it.
2. Bend the lens wipe paper into a few folds, and then wet it with cleaning fluid.
3. Gently wipe the surface of the lens with the wet lens paper. It needs to repeatedly wipe several times until the lens is clean that there are no dust and oil on the surface.
It is recommended to clean every day before work, but the equipment must be switched off.