Tamron SP AF 17-50mm f/2.8 XR Di II LD Aspherical (IF)

The Tamron SP AF 17-50mm f/2.8 XR Di II is a fast standard zoom designed for APS-C digital SLRs. It offers a constant f/2.8 aperture throughout the zoom range, making it a popular alternative to kit lenses for low-light photography and depth-of-field control. The optical design uses Extra Refractive Index (XR) glass to keep the lens barrel compact while maintaining sharpness and contrast across the frame. When buying used, pay attention to the rubber zoom and focus rings, which can sometimes expand or become loose with heavy use. SDS checks for 'zoom creep' and ensures the internal lens elements are clear of dust and debris. The autofocus motor should be tested for speed and accuracy, as older non-VC versions rely on the camera's internal motor or a basic built-in motor depending on the mount.