18-50mm f2.8 EX DC is a compact and lightweight zoom design despite its large
It boasts excellent correction for various types of aberration provided by one
SLD (Special Low Dispersion) glass element and two aspherical lenses. While
Super Multi Layer (SML) coating reduces flare and ghosting from which digital
cameras tend to suffer
The characteristics of digital SLR cameras were taken into consideration when
designing the lens power layout. The new advanced lens design corrects various
aberrations. This lens provides the utmost correction against lateral chromatic
aberration which is a serious problem for digital SLR cameras.
Sigma say the lens is specially coated to get the best colour balance while
cutting down flare and ghost caused by reflections from the digital image sensor
and lens. It has excellent correction for vignetting and superior peripheral
brightness is ensured.
A Special Low Dispersion (SLD) lens and two aspherical lens elements provide
excellent correction for all types of aberrations. The design produces a compact
and lightweight, yet robust, construction with an overall length of 84.1mm (3.3in.),
maximum diameter of 74.1mm (2.9in.) and weight of 445g (15.6oz).
This lens has a minimum focusing distance of 28cm (11in.). It is equipped with
an inner focusing system. The non-rotating front lens element makes the lens
suitable for using its petal-type lens hood and circular polarizing filters.
It is an ideal large aperture standard zoom lens for digital SLR cameras featuring
APS-C size image sensor.
Focal length 18-50mm
Minimum aperture f/22
Lens construction 15 Elements in 13 Groups
Angle of view 69.3°- 27.9°
Number of diaphragm blades 7pcs
Minimum focusing distance 28cm (11")
Maximum magnification 1:5
Filter Size 67mm
Lens hood Petal-type hood
Dimensions Diameter 74.1mm (2.9")X Length 84.1mm (3.3")
Fittings Sigma, Canon, Nikon-D, Pentax.