Sigma AF 85mm f/1.4 EX DG HSM (DX) - Review / Lab Test Report
Lens Reviews - Nikon / Nikkor (APS-C)
Article Index
Introduction
Analysis

Review by Markus Stamm and Klaus Schroiff, published May 2011

Special thanks to Thomas Koch for providing one of the review units!

Introduction

Recently we have had a look at how the Sigma AF 85mm f/1.4 EX DG HSM performed within its native full format scope (see here), but there are surely also lots of interested Nikon DX users out there who want to get an idea about the quality on the crop format. The lens behaves roughly like a "135mm f/2" lens here in terms of field-of-view and depth-of-field. As such it remains a short tele lens with typical applications such as studio- and portrait photography.

Note: we reused some portions of the corresponding full format article due to obvious similarities in some aspects.

Sigma is entering a market segment which has been traditionally dominated by the genuine manufacturers. In Nikon land we are talking about the well-established but not flawless AF-D 85/1.4 as well as the just recently introduced AF-S 85/1.4. There is also some competition by the Zeiss Planar T* ZF 85mm f/1.4 and the Samyang 85mm f/1.4 - both manual focus lenses and as such not everybody's darling. The Sigma features the same specifications as Nikon's latest offering but is significantly more affordable at just above half the price.

The build quality of the Sigma lens is excellent. It is a member of Sigma's professional grade "EX" (excellence) lineup. However, unlike previous EX lenses it does no longer feature a crinkle finish but a smooth rubber coating on top of a metal body. The new finish seems to be a better approach in our opinion - it doesn't collect as much dust for instance.

The rubberized focus ring operates smoothly. It has a constant physical length regardless of the focus setting. Sigma provides a petal shaped lens hood. DX users can mount an extra extension barrel for even more efficient light shading (see dedicated section below).

The Sigma has a rear focus group so its length remains constant regardless of the focus setting and the front element does not rotate. Using a polarizer is therefore no problem.

The HSM ("Hyper-Sonic-Motor") AF is very fast and virtually silent. The tested sample was spot-on in terms of accuracy. Full-time manual focusing is supported. Manual focusing is a bit on the delicate side because the focus path is rather short (which is, on the other hand, also a reason for the fast AF).

The Sigma AF 85mm f/1.4 EX DG HSM is a G-type lens and thus does not offer an aperture ring.

Thanks to an ultrasonic HSM drive the lens is fully compatible with all current Nikon DSLRs, including the motor-free entry-level models.

Hood extension for DX cameras

The Sigma AF 85mm f/1.4 EX HSM is a FX lens and consequently the lens hood is designed so that it does not vignette when the lens is mounted on a FX camera. On a DX camera though the hood could be longer without any risk to cause dark corners.

Sigma adresses this by adding a hood extension tube that makes the hood longer and thus offers potentially more protection:

The extension is attached to the bayonet mount on the lens and features the same bayonet again to actually mount the hood. The lens cap can be attached to the extension tube and since the tube features the same mount as the lens the hood can be mounted reversed for storage.

On paper this may sound like a good idea, however in practice it's something you try once or twice and then just leave the extension at home. The tube adds to the total length of the lens, which makes it less convenient to store in the bag. The whole setup (lens+tube+hood) feels a lot less solid and quite wobbly compared to lens and hood alone. A polarizing filter is impossible to adjust with both hood and tube mounted. And finally: after storing in reversed position, the hood occasionally comes of together with the extension tube, which then is quite cumbersome to remove from the inside of the hood.

The probably rather small gain in protection is hardly worth all the hassle.

Move the mouse cursor over the text marks below to see the different images
Hood extension tube With lens cap With reversed hood

Specifications
Equiv. focal length127.5 mm (full format equivalent)
Equiv. aperturef/2.1 (full format equivalent, in terms of depth-of-field)
Optical construction11 elements in 8 groups inc. 1x aspherical and 1x SLD elements
Number of aperture blades9 (circular)
min. focus distance0.85 m (max. magnification ratio 1:8.6)
Dimensions86 x 88 mm
Weight725 g
Filter size77 mm (non-rotating)
Hoodpetal-shaped, bayonet mount, supplied, plus extension tube for DX cameras
Other featuresLens provides distance (D) information to the camera, Silent Wave AF motor




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