Schneider-Kreuznach — 150mm f/5.6 plasmat normal lens for 4x5 view cameras, Copal 0 shutter
The Symmar-S 150mm f/5.6 was Schneider-Kreuznach's standard normal lens for 4x5 inch view cameras, introduced in 1961 as an improvement on the earlier convertible Symmar formula. It became one of the most widely fitted large-format optics of its era, later refined into the Apo-Symmar.
Optically it is a six-element, four-group symmetrical plasmat, multi-coated for improved contrast and mounted in a Copal 0 shutter with a 58mm filter thread. Image circle is roughly 211mm at f/22, giving generous front and rear movements on 4x5 sheet film while just covering 5x7.
Corner sharpness needs stopping down to around f/16-f/22, typical of plasmat designs from this period; wide open it softens off-axis. Photographers value the even field illumination and the movements it allows rather than any fast-aperture rendering.
Used examples circulate widely on the UK large-format market at modest prices. Buyers should test the Copal shutter across all speeds, check the glass for haze or separation between cemented groups, and confirm the iris blades move cleanly without oil residue.