![Amazon.com : Sigma 120-400mm f/4.5-5.6 AF APO DG HSM Telephoto Zoom Lens for Sony Digital SLR Cameras : Digital Slr Camera Lenses : Electronics Amazon.com : Sigma 120-400mm f/4.5-5.6 AF APO DG HSM Telephoto Zoom Lens for Sony Digital SLR Cameras : Digital Slr Camera Lenses : Electronics](https://m.media-amazon.com/images/I/91UkVyFYscL._AC_UF894,1000_QL80_.jpg)
Amazon.com : Sigma 120-400mm f/4.5-5.6 AF APO DG HSM Telephoto Zoom Lens for Sony Digital SLR Cameras : Digital Slr Camera Lenses : Electronics
![Am I hearing things? Today I recv'd this Sigma 120-400mm 1:4.5-5.6 APO DG OS HSM lens with a Nikon mount. When in AF mode I can hear what I think are gears Am I hearing things? Today I recv'd this Sigma 120-400mm 1:4.5-5.6 APO DG OS HSM lens with a Nikon mount. When in AF mode I can hear what I think are gears](https://preview.redd.it/br379tqide051.jpg?auto=webp&s=78eab2fc7f7ef9cbdeb8964d1d7e170eaa85b77a)
Am I hearing things? Today I recv'd this Sigma 120-400mm 1:4.5-5.6 APO DG OS HSM lens with a Nikon mount. When in AF mode I can hear what I think are gears
![Amazon.com : Sigma 120-400mm f/4.5-5.6 AF APO DG HSM Telephoto Zoom Lens for Sony Digital SLR Cameras : Digital Slr Camera Lenses : Electronics Amazon.com : Sigma 120-400mm f/4.5-5.6 AF APO DG HSM Telephoto Zoom Lens for Sony Digital SLR Cameras : Digital Slr Camera Lenses : Electronics](https://m.media-amazon.com/images/I/41yUrUtVM3L.jpg)
Amazon.com : Sigma 120-400mm f/4.5-5.6 AF APO DG HSM Telephoto Zoom Lens for Sony Digital SLR Cameras : Digital Slr Camera Lenses : Electronics
![Amazon.com : Sigma 120-400mm f/4.5-5.6 AF APO DG OS HSM Telephoto Zoom Lens for Nikon Digital SLR Cameras : Digital Slr Camera Lenses : Electronics Amazon.com : Sigma 120-400mm f/4.5-5.6 AF APO DG OS HSM Telephoto Zoom Lens for Nikon Digital SLR Cameras : Digital Slr Camera Lenses : Electronics](https://m.media-amazon.com/images/I/41lKBFdh1DL._AC_.jpg)