Dedicated for Digital SLR Cameras By incorporating an optical design for exclusive use with digital (APS-C) SLR cameras, this high power zoom lens provides the focal length equivalent to Tamron's 28-300mm (when converted to a 35mm format). Therefore, you can meet almost all photographic opportunities with this single zoom lens without changing lenses. When paired with...
Read moreDedicated for Digital SLR Cameras By incorporating an optical design for exclusive use with digital (APS-C) SLR cameras, this high power zoom lens provides the focal length equivalent to Tamron's 28-300mm (when converted to a 35mm format). Therefore, you can meet almost all photographic opportunities with this single zoom lens without changing lenses. When paired with the SP AF11-18mm zoom lens, simultaneously introduced by Tamron at Photokina, you can enjoy thoroughly digital SLR photography with the combined focal length coverage of 17-300mm. Optical System Uses Special Glass and is Optimized for Digital SLR Characteristics in order to Enhance Optical Quality in a Compact Design The new AF18-200mm high power zoom lens from Tamron 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 on-axis and lateral 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 Imager 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 Ghosting and flare caused by aberrations are annoying factors in digital SLR photography, so Tamron has adopted various countermeasures against the problem including the employment of Internal Surface Coatings (i.e., multiple-layer coatings on cemented surfaces of plural elements) and new multiple-layer coating technology on ordinary elements 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 MFD 0.45m over the Entire Zoom Range for 1:3.7 Macro Capability The new 18-200mm zoom lens realizes an MFD (Minimum Focus Distance) of 0.45m over the entire zoom range, which is better than that of the conventional 28-300mm