Tamron 18-200mm f3.5-6.3 AF XR DI II main features
Dedicated for Digital SLR Cameras - By incorporating an optical design for exclusive use with digital SLR cameras with smaller-size imagers, this high power zoom lens provides the same focal length, when converted to a 35mm format, equivalent to Tamron's 28-300mm.
Optical System Uses Special Glass and is Optimized for Digital SLR Characteristics in order to Enhance Optical Quality in a Compact Design - The AF18-200mm features an entirely new optical design using XR (Extra Refractive Index) glass in an innovative way in order to optimize the overall distribution of optical power throughout the entire zoom range. This design reduces various aberrations to the absolute minimum and achieves remarkable downsizing at the same time. In addition, three hybrid aspherical lens elements and two LD (Low Dispersion) glass elements are used to accomplish effective compensation of chromatic aberrations, a critical factor to enhance the optical quality in digital photography. As a result, the lens provides outstanding optical quality in a multi-purpose zoom lens.
Optical Design Dedicated to Digital SLR Photography by Optimizing the Angles of Incidences of Light Rays Reaching the Image Sensor - The zoom lens uses a new optical system designed to confine the changing angles of incidences of light rays reaching the imager within a certain scope over the entire image field from the center to the periphery, by considering the effects of variances due to zooming.
Enhanced Peripheral Illumination - Peripheral light fall-off is minimized when compared with that of conventional lenses for film cameras so that images are uniformly bright from the center to the periphery.
Outstanding Resolution - Since the lens is designed exclusively for digital SLR photography, it provides high image quality in terms of resolution, contrast and flatness of image field.
Internal Surface Coating to Reduce Ghosting and Flare - Internal Surface Coatings and new multiple-layer coating technology have been used in order to minimize reflections that occur when light enters through the front element and to reduce image degrading effects caused by the imagers themselves.
Revolutionary Minimum Focus Distance - 0.45m (17.7") for 1:3.7* Macro Capability - The new 18-200mm zoom lens realizes an MFD (Minimum Focus Distance) of 0.45m through the employment of a new optical/mechanical design configuration. Since the maximum magnification ratio at f=200mm is 1:3.7, you can enjoy close-up photography easily and conveniently.
Zoom Lock Mechanism Incorporated - The Zoom Lock prevents unwanted barrel extension when carrying the lens/camera combination.