Sigma 70-300mm F4-5.6 APO DG MAC

This is a classic, cost-effective super telephoto lens from the SLR era. Due to its APO (red ring) designation, its image quality and chromatic aberration control are significantly superior to Sigma's standard 70-300mm lens. Key specifications and selling points: Focal range: 70-300mm (on a full-frame camera; equivalent to approximately 105-450mm on an APS-C camera). Maximum aperture: F4 (70mm) - F5.6 (300mm). Macro function: Macro mode is available within the 200-300mm focal length range, with a maximum magnification ratio of 1:2. APO lens elements: Employs ultra-low dispersion glass, effectively reducing purple fringing and chromatic aberration common at telephoto ends. ⚠️ Crucial Compatibility Issues with Nikon F Mounts Before purchasing or using this Nikon mount lens, you must confirm the following two points, otherwise you may encounter issues with autofocus or aperture control: Aperture Ring Version (Determines Compatibility with Modern Cameras): Version with Aperture Ring: This older version has a manually rotating 1-22 aperture ring on the lens mount. When using this version on modern DSLRs, the aperture ring must be turned to its maximum (usually the red F22 mark) and locked to control the aperture via the camera body's dial. Version without Aperture Ring (G version): Purely electronic control, directly compatible with all Nikon DSLRs. Focus Motor Version (Determines Autofocus): This lens did not have a built-in focus motor when it was first released (it was driven by the camera body motor). If your Nikon camera is a D3000, D5000 series (such as D3200, D5300, D5600) or D40, D60, the lens will not autofocus and you will have to manually rotate the focus ring. For D7000 series cameras (such as D7100, D7200), D90, and all full-frame SLRs (such as D750, D850, D610, etc.), autofocus can be perfectly achieved through the camera's built-in motor. 💡