Filtergewinde

Filtergewinde is the term for the external screw thread on the front of many lenses and devices that allows screw-in filters to be attached. The size is defined by the filter diameter, stated in millimeters, and is usually printed on the lens front as something like Ø52, Ø58, Ø67, or Ø77. There is no universal standard across all brands, as each lens family uses its own nominal diameter. When a filter with a different size is needed, adapters in the form of step-up or step-down rings can be used, though these can introduce vignetting or mechanical play.

The thread pitch is another specification, and while many photographic threads share a similar pitch (often around 0.75 mm), the exact value varies by lens and manufacturer. It is important to consult the lens specifications or measure precisely if precise fit is required.

Common filters mounted via filtergewinde include protective UV or clear filters, circular polarizers, and neutral density filters, as well as specialized astronomical or infrared filters. When selecting filters, match the filter diameter to the lens thread and be mindful of potential effects on image quality, autofocus, and metering. Stacking multiple filters should be avoided when possible, as it can increase reflections and reduce sharpness, and may introduce vignetting on wide-angle lenses.

Installation and care are straightforward: align the threads and rotate clockwise until snug, taking care not to cross-thread. Keep the threads clean and dry, avoid overtightening, and store filters with end caps or in a protective case. See also filter thread sizes, step-up rings, and common lens filters.