Lens review

Sigma A 135 mm f/1.8 DG HSM

14 April 2017
Maciej Latałło

3. Build quality

The following chart  presents parameters of different 135 mm lenses designed for reflex cameras with apertures ranging from f/1.4 to f/2.0. As you see the Sigma’s physical dimensions and weight are very similar to those of slower Milvus and the Sony Zeiss 1.8/135, a lens with the same parameters. The fastest Mitakon is also the heaviest in this group. The Sigma sticks up among its rivals with its complex optical construction. Older 135 mm lenses, even as fast as f/2.0, could have only 5 elements inside and still the quality of images they provided was good. Complex optics of the Sigma includes as many as four low dispersion glass elements and suggests that this lens might deal with most of optical aberrations in an outstanding way.

What’s interesting, the Sigma 1.8/135 is just slightly smaller than the Sigma A 1.4/85 even though its entrance pupil is 75 mm in diameter while the latter’s entrance pupil is 60.7 mm in diameter.

In the photo below the tested lens is positioned next to the Sigma A 35 mm f/1.4 DG HSM.

Sigma A 135 mm f/1.8 DG HSM - Build quality

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The tested lens starts with a metal mount going round a contact plate, and a rear element, 30 mm in diameter, which doesn’t move. Areas around that element are nicely matted and darkened. The outer rim of the mount features a gasket.

Sigma A 135 mm f/1.8 DG HSM - Build quality

The proper body of the lens begins with a smooth, black ring made of metal on which you see a white dot, making an alignment with a camera easier, and an inscription ‘017’. Further on you find the name and parameters of the lens and above them a distance scale behind a window, expressed in feet and meters. There’s no depth of field scale of any kind. On the left side of the distance scale you see an “A” symbol meaning the lens belongs to the “Art” category, an inscription “MADE IN JAPAN”, a focusing mode switch (AF/MF) and an autofocus limiter switch which offers you three ranges: FULL, from 1.5 meters to infinity and from 0.875 of a meter to 1.5 meters.

Sigma A 135 mm f/1.8 DG HSM - Build quality

A huge manual focus ring as wide as 50 mm is the next part of the lens. Most of its surface is occupied by comfortable, rubber ribbing. The ring moves smoothly and is well-damped; running through the whole distance scale needs a turn through an angle of 150-160 degrees. It is a sensible value for a device equipped with autofocus.

Sigma A 135 mm f/1.8 DG HSM - Build quality

Right behind the manual focus ring you see a hood mount. The mount surrounds a non-rotating filter thread, 82 mm in diameter, which goes round a front element, as big as 75 mm in diameter.

Sigma A 135 mm f/1.8 DG HSM - Build quality

The construction of the lens consists of 13 elements positioned in 10 groups. Elements made of special low dispersion SLD (2 pieces) and FLD (also 2 pieces) are responsible to correct chromatic aberration. Inside there’s also a round aperture with nine blades which can be closed down to a value of f/16.

Buyers get both caps, a hood and a hard case with the lens in the box.

Sigma A 135 mm f/1.8 DG HSM - Build quality