Schneider-Kreuznach — 180mm f/5.6 plasmat lens for 5x7/4x5 view cameras, Copal 1 shutter
The Symmar-S 180mm f/5.6 sits between the 150mm and 210mm in Schneider-Kreuznach's 1961 Symmar-S range, commonly used as a standard lens on 5x7 inch cameras and a short-tele portrait option on 4x5. It was later succeeded by the Apo-Symmar version.
It shares the family's six-element, four-group symmetrical plasmat construction, multi-coated, generally fitted in a Copal 1 shutter with a 62mm filter thread. Image circle is roughly 248mm at f/22, covering 5x7 fully with movements to spare.
Wide open it is soft in the corners, sharpening progressively to f/16-f/22 like the rest of the range; its slightly longer focal length than the 150mm gives a flatter, less exaggerated perspective useful for portrait and product photography.
This focal length is common on the UK secondhand market and reasonably priced. Buyers should verify shutter speeds against a reference, check for coating scratches on the front element, and make sure the retaining rings are not cross-threaded.