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Sigma zoom lenses introduction
Dennis Hissink : October 27th 2003 - 01:00 CET
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 Sigma zoom lenses introduction : Sigma unveils two Sigma zoom lenses exclusively designed to suit the characteristics of digital SLR cameras. The first lens is the Sigma 18-50mm F3.5-5.6 DC lens. The image circle was designed to match the size of the image sensors of digital SLR cameras, and this produced a compact lens with a max. diameter of 60mm, overall length of 67.5mm and weight of only 245gr. The size of the image sensor is meant to be not larger than the APS sized image sensors. If cameras with larger image sensors or 35mm SLR cameras are used vignetting will occur on the picture surface. It has a variable angle of view of 76.5?-31.7?. If Sigma SD9 or SD10 digital cameras are used, the angle of view will be equal to 30-85mm.
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 Sigma - 18-50mm DC lens
The angle of view varies depending on the digital camera. The use of aspherical lenses provides correction for various aberrations throughout the entire zoom range and produce a high level of optical performance. The Sigma 18-50mm F3.5-5.6 DC lens has a minimum focusing distance of 25cm at all focal lengths and is capable of macro photography with a maximum magnification ratio of 1:3.5.
Sigma - 18-50mm DC lens specifications
- Focal Length :18-50mm
- Minimum Aperture :F22
- Lens Construction :8 Elements in 8 Groups
- Angle of View :76.5°-31.7°
- Number of Diaphragm Blades :7pcs
- Minimum Focusing Distance :25cm (9.8")
- Maximum Magnification :1:3.5
- Filter Size :58mm
- Lens Hood :Bayonet Hood
- Dimensions :Diameter 67.5mm (2.6")X Length 60mm (2.3")
- Mounts (AF) :Sigma, Canon, Nikon (D), Pentax
- Weight :245gr/8.6ounces
Sigma - 55-200mm DC lens
The second new lens is the new compact Sigma 55-200mm F4-5.6 DC lens. This compact telephoto Sigma zoom lens was exclusively designed for use with digital SLR cameras. The image circle was designed to match the size of the image sensors of digital SLR cameras that also allows compact body and lightweight with overall length of 84.6mm, and weight of only 310g. The size of the image sensor is meant to be not larger than the APS sized image sensors. If digital cameras with larger image sensors or 35mm SLR cameras are used vignetting will occur on the picture surface. It has a filter size of 55mm, maximum diameter of 70mm. This remarkably compact high performance zoom lens is ideally suited to a wide range of subjects. If Sigma SD9 or Sigma SD10 digital cameras are used, angle of view will be equal to 93-340mm focal length. The angle of view varies depending on the camera. This lens has a minimum focusing distance of 110cm (43.3") and maximum magnification of 1:4.
Sigma - 55-200mm DC lens specifications
- Focal Length :55-200mm
- Minimum Aperture :F22
- Lens Construction :10 Elements in 9 Groups
- Angle of View :29.0°-8.1°
- Number of Diaphragm Blades :8pcs
- Minimum Focusing Distance :110cm (43.3")
- Maximum Magnification :1:4.5
- Filter Size :55mm
- Lens Hood :Bayonet Hood
- Dimensions :Diameter 70mm (2.7")X Length 84.6mm (3.3")
- Mounts (AF) :Sigma, Canon, Nikon (D), Pentax
- Weight :310gr/10.9ounces
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