Tamron SP Autofocus 24-135mm f/3.5-5.6 AD Aspherical (IF) Lens for Canon SLR Cameras

From the Manufacturer Covering everything from 24mm real wide-angle through 135mm telephoto, this lightweight, compact lens represents a new departure in the high power zoom lens concept, with outstanding optical performance characteristics of the SP series. The optical system incorporates a new AD (Anomalous Dispersion) glass element, and four hybrid aspherical elements, resulting in ideal compensation of chromatic aberration and astigmatism. The minimum object distance of the lens is 15.7 inches over the entire zoom range. The 135mm telephoto achieves a maximum magnification ratio of 1:3.3, making macro photography possible. A zoom lock feature is included for enhanced portability. Hybrid aspherical elements provide the ultimate in compactness and image quality Through application of Tamron's exclusive Hybrid Aspherical technology (which can take the place of multiple optical elements) to LD glass, a never-before-possible level of image quality and compactness has been attained. Low-Dispersion Chromatic aberration is a form of optical noise that reduces the sharpness of an image. LD elements are made from special glass materials with extremely low dispersion indices (characteristics that separate or refract a ray of light into rainbow colors) that effectively compensate for chromatic aberration that is particularly a problem at the telephoto end. Anomalous Dispersion Anomalous Dispersion glass is a special optical glass that delivers an abnormally large partial dispersion ratio (amount of dispersion at a given wavelength range within visible light) relative to a specific wavelength zone. By combining AD glass elements with elements made of normal glass with different dispersion characteristics, dispersion factors of a specific wavelength can be controlled, resulting in effective compensation of on-axis chromatic aberration on telephoto lenses, or lateral chromatic aberration associated with wide-angle lenses of conventional optical configuration. Internal Focusing System Aside from enhancing lens maneuverability, Tamron's Internal Focusing System provides additional benefits to users. Chief among them is a reduced Minimum Object Distance (M.O.D.) throughout its entire focal length range. Additionally, it improves optical characteristics by minimizing illumination loss at image corners and suppresses aberrations that are caused by focusing positions. Another benefit of Internal Focusing is a stationary focusing ring--regardless of the focusing action. Quick and subtle manual focus adjustments are now a snap. What's in the Box: Lens and lens hood

• Covers 24mm real wide-angle through 135mm telephoto
• Internal focusing system maintains overall length during focusing
• Low-dispersion glass compensates for chromatic aberration
• Hybrid aspherical elements for compactness and image quality
• Mount compatible with Canon AF SLR cameras