The Sigma 24mm f/1.8 EX DG is wide-angle lens which features a fast f/1.8 maximum aperture for use in low-light situations, and macro focusing capability to a reproduction ratio of 1:2.7. It uses aspherical lens elements. Though intended for 35mm film and full-frame digital SLRs, this lens is available for several makes of APS-C digital SLR cameras, where the angle of view is similar to a moderate wide-angle lens (in the 35mm-40mm range, depending on the size of the D-SLR sensor).

Sigma 24mm f/1.8 EX DG

Maker	Sigma Corporation
Technical data
Type	wide angle lens
Focal length	24 mm
Crop factor	84 degrees (FX or 35mm), 62 degrees ( DX or APS-C)
Aperture (max/min)	f/1.8, f/22
Close focus distance	18 cm
Max. magnification	1:2.7
Construction	10 elements in 9 groups
Features
Short back focus	n/a
Ultrasonic motor	n/a
Lens-based stabilization	No
Macro capable	Yes
Unique features	Very fast maximum aperture
Application	low-light, landscape, macro, general purpose wide angle
Physical
Max. length	82 mm
Diameter	84 mm
Weight	485 g
Filter diameter	77mm
Accessories
Lens hood	included (bayonet)
Case	included (soft)
Angle of view
Horizontal	73 degrees (FX or 35mm)/54 degrees (DX or APS-C)
Vertical	54 degrees (FX or 35mm)/37 degrees (DX or APS-C)
Diagonal	84 degrees (FX or 35mm)/62 degrees (DX or APS-C)
Retail info
MSRP	$450 (street price $340) USD

This lens is capable of macro photography, with minimum focusing down to 18 cm/7.1" (reproduction ratio 1:2.7). It incorporates a floating focus system in order to minimize distortion, spherical aberration and astigmatism, and provides high performance at all shooting distances. The high reproduction ratio and wide angle of view allow capturing high quality images not only of a subject but also the surrounding scenery.

The Lens was introduced in 2001.