SLR is the commonly used for “Single-lens reflex” cameras, meaning cameras with interchangeable lenses and through-the-lens viewing (and metering) using mirrors (hence, ‘reflex’) and prisms.

Cross section of SLR with lens
Cross section of SLR with lens. Photo by Lionel Allorge on Wikimedia commons

While often also referred to simply as reflex cameras, originally the term ‘Single-lens’ (reflex) was to distinguish these cameras from their predecessors: Twin-lens reflex cameras (or TLR’s).

« Back to Glossary Index