You'll get the F-- error if the lens is older, e.g. most manual-focus lenses (AI/AI-S) have no chip. However, some manual-focus AI-P lenses such as the 45mm/f2.8 P do. It has nothing to do with auto focus and its mechanism. All Nikon AF lenses since the late 1980's have that chip. Tamron SP 17-50 2.8 Di II Canon FZ ECD Circuit Board AN16-911 Add to cart Add to Wishlist Compare $ 15.91 Tamron SP 17-50 2.8 Di II Nikon FZ ECD Circuit Board AE16-911 Read more Add to Wishlist Compare View: 9 Categories Accessories Equipment Light Seals Owner's Manuals Parts Beseler Enlargers Canon AW WP Housings Battery Grips Camera Chip Fuses The large-aperture and excellent optical performance that this lens offers is ideal for low-light photography and enriched creative picture composition possibilities. The new lens delivers pin sharp results and remarkable contrasts throughout the entire focal length range. With an aperture of F/2.8 impressive photos with smooth, even bokeh Tamron's SP AF17-50mm F/2.8 XR Di II VC LD Aspherical (IF)is a high-speed, wide-to-moderate-telephoto zoom lens designed for Canon DSLR cameras with smaller sensors. It covers the very popular 17-50mm focal length range (equivalent to 26-78mm in the full-frame 35mm format) making it extremely versatile. There is no haze on inside of the lens. Including Front Lens Cap. Rear Lens Cap. I will provide courteous and responsive service. There is no balsam separation. It has no tiny fungus. $750 cheaper than Nikon's comparable 17-55mm f/2.8. What's Not $40 more expensive than the comparable Sigma. 17-50mm (17.36-50.37 tested), f/2.8 (f/2.74-2.93 tested), 16 elements in 13 groups. Focusing turns 50 degrees clockwise. Zoom ring turns 80 degrees counterclockwise. Focal lengths marked at 17-, 24-, 35-, and 50mm. Posts: 2,636. Tamron 17-50mm/2.8 Loose Filter Ring? I put my 17-50 on the K20D yesterday and when I unlocked the hood from it's storage position I noticed the hood/filter ring is loose (it jiggles a little). I haven't dropped, banged or otherwise abused my precious so I'm curious if anyone else has had the same thing happen. I've used a Tamron 17-50 f/2.8 for two years and it's a superb lens. Use it for street photography and street portraits. No issues with AF - plenty fast enough. Less than half the price of the Canon 17-55. Smaller and lighter as well. Easy choice for me. It has been a superb lens; love the way portraits are rendered. Thanks for your time! Amazon has the Tamron SP 90mm F2.8 macro Brand New for $499.00 so it seems like $400. is quite a bit of $$$ to fix a used lens you paid $200 for. Either way you are out the $50. You need to decide if you really use. This item: Tamron SP 17-50mm F/2.8 XR Di-II VC LD Aspherical for Nikon APS-C Digital SLR Cameras (6 Year Tamron Limited USA Warranty) $399.00 Get it as soon as Saturday, Jul 16 FREE Shipping on orders over $25 shipped by Amazon Tiffen 46UVP 46mm UV Protection Filter $9.99 A fast, stabilised, standard zoom lens for Canon and Nikon cameras with APS-C sized sensors.Tamron's SP AF17-50mm f/2.8 XR Di II VC lens is designed exclusively for cameras with APS-C sized sensors and covers the popular standard zoom range of focal lengths. On Nikon cameras it is equivalent to 26-78mm in 35mm format, while on the Canon EOS 40D body we used for our tests, the equivalent range A fast, stabilised, standard zoom lens for Canon and Nikon cameras with APS-C sized sensors.Tamron's SP AF17-50mm f/2.8