Lens cover

A lens cap is placed to protect the lens from dirt and damage to a lens. In the early days of photography the lens cap served as a camera shutter, through which the exposure of the film material was controlled.

With interchangeable lenses, a distinction is made between the front cover and back cover. The front cover protects the front lens, which is open at a ready-made camera. The back cover is attached to the camera connection of the lens, while it is not attached to the camera.

Front cover are now mostly made ​​of plastic and are snapped with a spring mechanism in the filter thread of the lens, so it easy to set up and must be removed. The required size of the cover results from the filter thread diameter of the lens. Simpler models made ​​of plastic stick through a snug fit on the outer diameter of the lens. For higher quality versions of metal for fitting fit and sufficiently tight fit can be achieved by a Velvet trim at the inner edge of the lid. There are also lens cap to be screwed into the filter thread.

The design of the back cover is on the lens of the respective camera connection system dependent, which may be formed as a screw thread or bayonet connection. Back cover of different camera systems are therefore usually not compatible with each other.