Sigma 18–50mm f/2.8 EX DC Macro lens

18-50mm f/2.8 EX DG Macro

Maker	Sigma Corporation
Technical data
Focal length	18-50mm
Aperture (max/min)	f/2.8 - f/22
Close focus distance	28cm / 11 in.
Max. magnification	1:3
Diaphragm blades	7
Construction	15 elements in 13 groups
Features
Short back focus	No
Lens-based stabilization	No
Macro capable	Yes
Application	portrait
Physical
Max. length	85.8mm / 3.4 in.
Diameter	79mm / 3.1 in.
Weight	450g / 15.9 oz.
Filter diameter	72 mm
Accessories
Lens hood	Petal
Angle of view
Diagonal	69.3° - 27.9°
History
Introduction	2006
Retail info
MSRP	$700.00 USD USD

The Sigma 18-50mm f/2.8 EX DC Macro is a wide to normal angle, zoom lens made by the Sigma Corporation.

The lens is produced in Canon EF mount, Four Thirds System, Nikon F-mount, Pentax K mount, the SA mount, and the Sony/Minolta AF Mount varieties, all have the same optical formula.

The lens is designed for digital crop DSLR with an APS-C sized sensor. Because of this, if the lens is used on a non-crop body, such as a Nikon D700, it will cause significant mechanical vignetting. When used on a body with a field of view compensation factor of 2x (Four Thirds body) it provides a field of view equivalent to a 36-100mm lens mounted in a 35mm body. In a 1.6x body, such as the Canon EOS 450D, it provides a less narrow field of view, equivalent to a 29-80mm lens mounted on a 35mm frame body. With a 1.5x body such as the Nikon D300 It provides a less narrow field of view, equivalent to a 27-75mm lens mounted on a 35mm frame body.

Technical information

The 18-50mm f/2.8 EX DC Macro is a consumer-level lens. It is constructed with a plastic body and a metal mount. The lens features a distance window with depth of field scale. A 7-blade, maximum aperture of f/2.8 gives the lens the ability to create depth of field effects. The optical construction of the lens contains 15 lens elements, including two aspherical lens elements, one SLD (Special Low Dispersion) element, and one ELD (Extraordinary Low Dispersion) element. The lens uses an internal focusing system, powered by a micro motor. Auto focus speed of this lens is moderate, but because of its focal length, auto focus time is not long. The front of the lens does not rotate, but the focusing ring does, when using auto focus. The lens uses an extending inner lens barrel when zooming, this allows a more compact design, and does not rotate while zooming.^[1][2]

HSM variant

In 2007, Sigma released a HSM version of the 18-50mm f/2.8 EX DC Macro, called the 18-50mm f/2.8 EX DC Macro HSM. This lens is available for Nikon F-mount only. The lens has the same optical formula as the non-HSM lens, but is 0.5 mm shorter, and 85 g (18.9 oz.) heavier. The lens has a closer minimum focus distance of 20 cm, but because of the larger Nikon DX sensor size, the magnification rating is still 1:3. Also because of larger sensor size, the stated angle of view is 76.5º - 31.7º, though theses angles are still obtainable on the non-HSM version.^[3]

See also

• List of Nikon compatible lenses with integrated autofocus-motor

References

External links

Wikimedia Commons has media related to Sigma 18-50mm F2.8 EX DC Macro.

Four Thirds System lenses timeline

Wide-angle Standard Telephoto Super Telephoto 4.5 7 8 9 10 11 12 14 17.5 18 20 22 24 25 30 35 40 42 45 50 54 55 60 70 90 100 105 125 135 150 180 200 250 300 400 500 800 2003 Olympus Zuiko Digital 14-54mm F2.8-3.5 Olympus Zuiko Digital 50mm F2.0 Macro Olympus Zuiko Digital 50-200mm F2.8-3.5 2004 Olympus Zuiko Digital 11-22mm F2.8-3.5 Olympus Zuiko Digital 14-45mm F3.5-5.6 Sigma 18-50mm F3.5-5.6 DC Sigma 18-125mm F3.5-5.6 DC Olympus Zuiko Digital 40-150mm F3.5-4.5 Sigma 55-200mm F4-5.6 DC Olympus Zuiko Digital ED 150mm F2 Olympus Zuiko Digital ED 300mm F2.8 2005 Olympus Zuiko Digital ED 7-14mm F4 Olympus Zuiko Digital 17.5-45mm F3.5-5.6 Olympus Zuiko Digital 35mm F3.5 Macro Olympus Zuiko Digital ED 35-100mm F2 Olympus Zuiko Digital ED 90-250mm F2.8 2006 Olympus Zuiko Digital 8mm F3.5 Olympus Zuiko Digital ED 14-42mm F3.5-5.6 Leica D Vario-Elmarit 14-50mm F2.8-3.5 ASPH Sigma 18-50mm F2.8 EX DC Olympus Zuiko Digital ED 18-180mm F3.5-6.3 Sigma 24mm F1.8 EX DG Sigma 30mm F1.4 EX DC HSM Olympus Zuiko Digital ED 40-150mm F4-5.6 Sigma 50-500mm F4-6.3 EX DG HSM Sigma 105mm F2.8 EX DG Macro Sigma 150mm F2.8 EX DG APO Macro HSM 2007 Olympus Zuiko Digital ED 12-60mm F2.8-4 SWD Leica D Vario-Elmar 14-50mm F3.8-5.6 ASPH Leica D Summilux 25mm F1.4 ASPH Olympus Zuiko Digital ED 70-300mm F4-5.6 Sigma 135-400mm F4.5-5.6 DG APO Sigma 300-800mm F5.6 EX DG HSM APO 2008 Olympus Zuiko Digital ED 9-18mm F4-5.6 Sigma 10-20mm F4.0-5.6 EX DC HSM Olympus Zuiko Digital ED 14-35mm F2 SWD Olympus Zuiko Digital 14-54mm F2.8-3.5 II Leica D Vario-Elmar 14-150mm F3.5-5.6 ASPH Olympus Zuiko Digital 25mm F2.8 Sigma 50mm F1.4 EX DG HSM Olympus Zuiko Digital ED 50-200mm F2.8-3.5 SWD 2009 Sigma 70-200mm F2.8 EX DG Macro II HSM 20?? Sigma 4.5mm F2.8 EX DC HSM Sigma 10mm F2.8 EX DC HSM Sigma 50-150mm F2.8 II APO EX DC HSM Green background indicates lenses with image stabilization. Red background indicates unconfirmed lenses (rumors, please edit).