Mamiya Mamiya-Sekor 50mm f/2 SX - M42-mount

The Mamiya-Sekor 50mm f/2 SX is a standard prime lens originally designed for Mamiya's 35mm SLR cameras using the M42 screw mount. The 'SX' designation indicates it features a specific lug for aperture indexing on Mamiya bodies, though it remains compatible with standard M42 adapters. It is known for its solid metal construction and provides a classic rendering with natural colour reproduction and decent sharpness when stopped down. When buying this M42 lens, the most common issue is the 'sticky' aperture caused by oil on the blades, which is a frequent fault in older Sekor optics. SDS checks the diaphragm for snappy operation and inspects the glass for scratches, as these lenses often lacked protective filters. The SX lug can sometimes interfere with flat M42 adapters, so we ensure the rear mount is undamaged and the focus ring operates smoothly without excessive play.