Pentax SMC Pentax-M 50mm f/4 Macro - Pentax K Mount

The SMC Pentax-M 50mm f/4 Macro is a manual focus K-mount lens designed for close-up photography. It offers a 1:2 magnification ratio (half life-size) without additional accessories. As part of the 'M' series, it is notably compact and features a robust all-metal construction. The lens is corrected for flat-field reproduction, making it excellent for document copying and detailed macro work, while also serving as a sharp standard prime for general use. Check the long-throw focus helical for smoothness; if the lubricant has dried, the movement may feel gritty or uneven. Inspect the aperture blades for oil contamination, which can cause slow closure and overexposure. SDS examines the internal glass for haze, which is sometimes found in older M-series lenses. The front element is deeply recessed, but it is still worth checking for scratches on the coating.