The 18-200mm f/3.5-6.3 DT Telephoto Zoom Lens from Sony is a DT-series Alpha lens that has been optimized for cropped image sensors, and as a result it is not recommended for use with larger full-frame cameras. Its optics have been optimized for a small diameter image circle in order to work with the APS-C size sensor used with digital SLR cameras. When used with a digital SLR camera, the equivalent focal length for this lens is 27-300mm.
It is constructed of 15 elements in 13 groups - two of them being Extra-low Dispersion (ED) glass and another three aspherical glass elements - which all help to deliver sharp, clear photos throughout the zoom range. It has a minimum focusing distance of 1.5' and a non-rotating front-end filter diameter of 62mm, allowing you to use circular polarizing filters without difficulty.
Note: Not compatible with 35mm or "full-frame" digital SLR cameras (e.g. A900, film cameras)
- APS-C 35mm Equivalent: 27-300mm
- This 18-200mm lens has an 11x zoom factor, but its viewing angle becomes the 35mm equivalent of a 27-300mm lens when attached to the cropped APS-C cameras it was designed for.
- Aperture Range: f/3.5-40
- With a maximum aperture of f/3.5 and minimum of f/40 this lens' high speed means you can capture images in darker conditions using faster shutter speeds and lower ISO sensitivity.
- Optimized For APS-C Size / DT-Format Alpha & Minolta DSLRs
- Intended for smaller, cropped Sony Alpha cameras, DT lenses employ an optical system that is specifically designed for digital cameras which incorporate an APS-C size image sensor.
- 2x Extra-Low Dispersion (ED) Elements
- To reduce chromatic aberrations, most noticeable when zoomed all the way in, the extra-low dispersion glass corrects for certain wavelengths of light - producing sharper images with truer colors.
- 3x Aspherical Glass Lens Elements
- These precision lens elements correct distortion for sharper, more visually accurate images across the entire zoom range of the lens.
- Internal Focusing
- Internal lens elements move, so the overall length does not change, creating a lens that focuses more quickly and doesn't change balance.
- 7x Circular Aperture Blades
- Circular aperture blades produce smooth, rounded bokeh background effects when capturing spot-light sources in your pictures. Because the aperture blades form a near circle at the wide openings used for low-light shots, spot-light sources have a pleasing circular defocused effect.
- Filter Diameter: 62mm
- The 62mm front filter thread does not rotate, allowing rotating polarizing filters to be used.