BlattverschlussFlachverschluss

BlattverschlussFlachverschluss is a term found in German-language photography literature that is not a standard technical category on its own. It is sometimes used to refer collectively to two main shutter families: Blattverschluss (leaf shutter) and Flachverschluss (flat or focal-plane shutter). In practice, the two shutter types represent distinct design philosophies and are not interchangeable, but some catalogs or explanations use the combined term to discuss them side by side.

Blattverschluss refers to a shutter built from multiple thin metal blades that sit within the lens housing. When released, the blades open and close to control exposure. Leaf shutters are compact, provide relatively quick and repeatable exposure control, and commonly offer high flash synchronization speeds because the entire aperture plane can be exposed at once. They are typically found in medium-format cameras and many rangefinder lenses, where the shutter is integrated into the lens assembly.

Flachverschluss denotes a shutter mechanism located in the camera body, usually a focal-plane or flat shutter that travels a curtain or pair of curtains across the film or sensor plane. Flachverschluss systems can achieve a broad range of shutter speeds, including very fast ones, but flash synchronization at high speeds is typically more complex. They have been widely used in 35mm SLRs and other camera formats, particularly in the early to mid-20th century and in many modern digital bodies that adopt focal-plane designs.

Differences between the two include physical placement (lens vs body), speed capabilities, flash synchronization characteristics, and maintenance considerations. The term BlattverschlussFlachverschluss is mainly an umbrella reference rather than a precise technical specification.