Sigma 20-40mm F/2.8 EX DG Aspherical IF

Wide-angle zoom lens • Digital era • Discontinued

  • Announced:
  • · August 2001
  • Production status:
  • ● Discontinued
  • Country of design:
  • · Japan
  • Original name:
  • · SIGMA ZOOM 20-40mm 1:2.8 DG EX ASPHERICAL IF
  • Class:
  • · Fast full-frame wide-angle zoom lens
  • · Professional model

Abbreviations

EX Professional lens with high quality optics and robust build. Meets the highest standards and provides excellent performance and flawless image quality unachievable with traditional optical technologies.
DG The lens is designed for 35mm digital cameras but can be also used on APS-C digital cameras.
IF Internal focusing.

Specification

Optical design:
35mm full frame
20mm - 40mm [2X zoom ratio]
F/2.8 across the focal length range
17 elements in 13 groups
2 ASPH
Internal focusing (IF)
Canon EF [44mm]
Minolta/Sony A [44.5mm]
Nikon F [46.5mm]
Pentax K [45.5mm]
Sigma SA [44mm]
94.5° @ 20mm - 56.8° @ 40mm (35mm full frame)
On Canon EOS APS-C [1.59x] cameras:
35mm equivalent focal length range:
31.8mm - 63.6mm (in terms of field of view)
35mm equivalent speed range:
F/4.5 (in terms of depth of field)
Diagonal angle of view:
68.4° @ 20mm - 37.6° @ 40mm
On Sony DSLR-A/SLT-A APS-C [1.53x] cameras:
35mm equivalent focal length range:
30.6mm - 61.2mm (in terms of field of view)
35mm equivalent speed range:
F/4.3 (in terms of depth of field)
Diagonal angle of view:
70.5° @ 20mm - 38.9° @ 40mm
On Nikon D APS-C [1.53x] cameras:
35mm equivalent focal length range:
30.6mm - 61.2mm (in terms of field of view)
35mm equivalent speed range:
F/4.3 (in terms of depth of field)
Diagonal angle of view:
70.5° @ 20mm - 38.9° @ 40mm
On Pentax K APS-C [1.53x] cameras:
35mm equivalent focal length range:
30.6mm - 61.2mm (in terms of field of view)
35mm equivalent speed range:
F/4.3 (in terms of depth of field)
Diagonal angle of view:
70.5° @ 20mm - 38.9° @ 40mm
On Sigma SD APS-C [1.74x] cameras:
35mm equivalent focal length range:
34.8mm - 69.6mm (in terms of field of view)
35mm equivalent speed range:
F/4.9 (in terms of depth of field)
Diagonal angle of view:
63.7° @ 20mm - 34.5° @ 40mm
Diaphragm mechanism:
Diaphragm type:
Automatic
Aperture control:
None; the aperture is controlled from the camera (Canon EF, Minolta/Sony A, Sigma SA)
Aperture ring (Manual settings + Auto Exposure setting) (Nikon F, Pentax K)
9 (nine)
Zooming:
Zoom mechanism:
Manual
Zoom control:
Zoom ring
Zoom type:
Rotary
Zooming method:
Extends while zooming
Focusing:
0.30m
1:4.6 @ 40mm
Focusing modes:
Autofocus (A), Manual focus (M)
Autofocus motor:
Micromotor (Canon EF, Sigma SA)
In-camera motor (Nikon F, Pentax K, Minolta/Sony A)
Manual focus control:
Focusing ring
Focus mode selector:
Sigma Dual Focus System (Canon EF, Sigma SA)
Focus Clutch Mechanism (Nikon F, Pentax K, Minolta/Sony A)
Manual focus override in autofocus mode:
-
Optical Stabilizer (OS):
-
Physical characteristics:
595g (Nikon F)
⌀89×107.8mm (Nikon F)
-
-
Accessories:
Screw-type 82mm
LH875-02 - Bayonet-type petal-shaped
Not compatible

Source of data

  • Manufacturer's technical data.

Manufacturer description #1

20-40mm lens with F2.8 throughout its zoom range, from ultra-wide 94.5 degrees to near-standard 56.8 degrees angle of view, for photographers to shoot more creatively from various angles and zoom perspectives. This lens is perfectly suited for indoor shootings even in dim light without worrying about blurring in photos. The lens' 30cm minimum focusing distance is useful for closeups, giving photographers plenty of capability to use the zoom to adjust composition and concentrate on detail, as desired. Maximum magnification is 1:4.6. Aspherical lens elements in front and rear lens groups compensate for astigmatic and spherical aberration, respectively. Among the practical high-performance features of the lens are DF (Dual Focus) mechanism for optimal handling stability during autofocus operation; a wider-than-conventional focal ring for superior manual focusing operation; and an inner focusing system that eliminates front lens rotation during focusing, and allows use of the standard petal-type hood accessory, which is excellent at blocking out extraneous light.

Manufacturer description #2

Sigma has created a new 20-40mm lens with f/2.8 throughout its zoom range, from ultra-wide 94.5 degree to near-standard 56.8 degree angle of view, allowing photographers to shoot more creatively from various angles and zoom perspectives. With a fast f/2.8 maximum aperture, superior peripheral brightness is ensured. This lens is perfectly suited for indoors, even in dim light. These features also make this lens desirable for use with Digital SLR Cameras.

The 30cm minimum focusing distance is useful for closeups, giving photographers plenty of capability to use the zoom to adjust composition and concentrate on detail. Maximum magnification is 1:4.6. A short focus distance and a minimum aperture of f/22 provides greater depth of field.

Aspherical lens elements in front and rear lens groups compensate for astigmatic and spherical aberration, respectively. By reducing aberration to an absolute minimum, this lens overcomes a major impediment to zoom lens performance.

Among the practical high-performance features of the lens are DF (Dual Focus) mechanism for optimal handling stability during autofocus operation; a wider-than-conventional focus ring for superior manual focusing operation; and an inner focusing system that eliminates front lens rotation during focusing, and allows use of the standard petal-type hood accessory, which is excellent at blocking out extraneous light.

Notes

  • The autofocus will not be available with Nikon D40, D40X, D60, D3000-D3500, D5000-D5600 digital SLR cameras.

Lenses with similar focal length range

■Canon EF mount (3)
Canon EF 17-40mm F/4L USM • ⌀77Pro 2003 ●compare52
Tamron SP AF 20-40mm F/2.7-3.5 Aspherical [IF] 166D • ⌀77 1994 ●compare13
Tamron SP AF 20-40mm F/2.7-3.5 Aspherical [IF] 266D • ⌀77 2000 ●compare13
■Pentax K mount (1) · APS-C
HD Pentax-DA 20-40mm F/2.8-4 ED DC WR Limited • ⌀55 2013 ●compare82
■Minolta/Sony A mount (2)
Tamron SP AF 20-40mm F/2.7-3.5 Aspherical [IF] 166D • ⌀77 1994 ●compare13
Tamron SP AF 20-40mm F/2.7-3.5 Aspherical [IF] 266D • ⌀77 2000 ●compare13
■Nikon F mount (2)
Tamron SP AF 20-40mm F/2.7-3.5 Aspherical [IF] 166D • ⌀77 1994 ●compare13
Tamron SP AF 20-40mm F/2.7-3.5 Aspherical [IF] 266D • ⌀77 2000 ●compare13

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