Sigma 75-300mm f/4-5.6 Zoom - Unknown Mount

A versatile telephoto zoom lens, the 75-300mm f/4-5.6 covers a significant range, making it suitable for wildlife and sports photography. It was produced in various versions, including both manual and autofocus, generally featuring a push-pull zoom design. Despite its long reach, it remains relatively portable, though it requires good light at the 300mm end due to the f/5.6 maximum aperture. Common issues with these zooms include zoom creep, where the barrel extends under its own weight when pointed downwards. The long internal barrels can also act as bellows, drawing in dust; SDS checks the internal optics for significant particles and haze. For autofocus versions, the drive mechanism is tested for consistency and to ensure there are no broken teeth in the AF gears.