Sigma 70-210mm f/4-5.6 Zoom-K MC - Unknown Mount

The Sigma 70-210mm f/4-5.6 Zoom-K MC is a classic manual focus telephoto lens featuring Multi-Coating (MC) to improve light transmission and reduce flare. It covers the popular telephoto range used for sports, portraits, and nature photography. The lens usually employs a push-pull zoom design, allowing the user to adjust both focus and focal length simultaneously, which is advantageous for tracking moving subjects on film cameras. Inspect the push-pull barrel for excessive play or 'creep' when the lens is pointed vertically. SDS checks the multi-coating for any signs of cleaning marks or coating loss on the front and rear elements. The aperture should be tested to ensure the blades are dry and move freely. Additionally, check for internal haze or fungal growth, which can be more prevalent in older telephoto lenses with multiple glass groups.