The Tamron 200 mm f/ 3.5 Adaptall model CT-200 Lens. Specs. MTF Charts. User Reviews.
Amazon.com : Tamron AF 200-500mm f/5.0-6.3 Di LD SP FEC (IF) Lens for Canon Digital SLR Cameras (Model A08E) (Discontinued by Manufacturer) : Camera Lenses : Electronics