World Library  
Flag as Inappropriate
Email this Article

Sigma 18–50mm f/2.8 EX DC Macro lens

Article Id: WHEBN0021771518
Reproduction Date:

Title: Sigma 18–50mm f/2.8 EX DC Macro lens  
Author: World Heritage Encyclopedia
Language: English
Subject: Sigma Corporation, List of Nikon F-mount lenses with integrated autofocus motor
Publisher: World Heritage Encyclopedia

Sigma 18–50mm f/2.8 EX DC Macro lens

18-50mm f/2.8 EX DG Macro

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


This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.

Copyright © World Library Foundation. All rights reserved. eBooks from World eBook Library are sponsored by the World Library Foundation,
a 501c(4) Member's Support Non-Profit Organization, and is NOT affiliated with any governmental agency or department.