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Sigma AF 20 mm f/ 1.8 EX DG ASPHERICAL RF Lens

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Sigma AF 20 mm f/ 1.8 EX DG ASPHERICAL RF lens

Sigma AF 20 mm f/ 1.8 EX DG ASPHERICAL RF lens

Sigma AF 20 mm f/ 1.8 EX DG ASPHERICAL RF lens

Sigma AF 20 mm f/ 1.8 EX DG ASPHERICAL RF lens

MTF-charts

Sigma AF 20 mm f/ 1.8 EX DG ASPHERICAL RF MTF Chart

Optical design

Sigma AF 20 mm f/ 1.8 EX DG ASPHERICAL RF optical design

Format: 35mm SLR

Type: Prime lens

Focusing: Auto Focus (AF)

Lens mounts: Canon EF, EF-S, Sony A / Minolta A, Nikon F (FX, DX), Pentax K, Sigma SA

First year of production: 2000

Optical design: 13 elements in 11 groups

User reviews (1)

Photos (16)

Tests (0)

Owners (7)

Views (8747)

Average price: $603

Specifications:

Focal lengthMax. apertureMin. apertureBladesMin. Focus (m.)Filter Ø (mm.)Weight (gr/oz)Length (mm/in)
20mmf/1.8f/2290.282520/18,387/3,4

Additional information:

The Sigma AF 20 mm f/ 1.8 EX DG ASPHERICAL RF  is a wide-angle lens for modern film and digital Sigma cameras.

It is the fastest 20mm lens on today's market.

With a lens speed  of 1.8, it enables shooting in poor lighting conditions without a tripod or flash.

Two aspherical elements in the optical scheme effectively combat distortion, chromatic aberration and astigmatism.

 The Sigma AF 20mm f/1.8 EX DG ASPHERICAL RF blurs at f/1.8 especially when the subject is more than 3m away. Yet, the results are quite acceptable. The situation remains the same up to f/2.2. From f/2.2 it is sharp. And it is very sharp from f/4 onwards.

Vignetting is visible up to f/2.2, it is not manifested farther.

There are insignificant drops in resolution on the edges.

Focusing is internal. Manual focusing can be switched on at any time by turning the focusing ring. The front lens does not rotate during focus operations, which enables the use of special caps, petal hood, as well as gradient and polarized filters.

The pictures taken with this lens have beautiful coloring and good contrast. The lens is quite well resistant to back and side lighting, especially with a hood.

The Sigma AF 20 mm f/1.8 EX DG ASPHERICAL RF is perfect for shooting landscapes, architecture, interiors, as well as for genre photography. This is really  a universal and convenient focal length. It is ideally fit for video shooting on modern SLR cameras.

As soft carrying case and a petal hood are included with the lens.

Attention! The autofocus won't function on Nikon D40, D40x, D60, D3000, D5000 cameras which are not equipped with the built-in motor.


Links to online resources:
Posted by: Sergei Borodin   Date of publication: 17.08.2010



Photos taken with this lens Sigma AF 20 mm f/ 1.8 EX DG ASPHERICAL RF:


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Autor: Sergei Borodin
5 0 2495

The wall
Autor: Sergei Borodin
5 0 1844

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Autor: Sergei Borodin
5 0 2037

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Autor: Sergei Borodin
5 0 3117

Mechanical quality4.504
Optical quality4.754
Usability5.003
Pricing / Value4.003
Bokeh4.605
Overall lens rating
4.57

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