Sigma 100-400mm f/5-6.3 DG DN OS Contemporary - Review / Test
Lens Reviews - Sony Alpha (Full Format)

Review by Klaus Schroiff, published December 2021


The Sigma 100-400mm f/5.6-6.3 DG DN OS is the mirrorless camera version of the highly popular Sigma 100-400mm f/5.6-6.3 DG OS HSM. While very similar in shape, there are some subtle differences - including a modified optical formula.  Unlike the older lens, it is at least possible to attach an (optional) tripod mount. The HSM has been replaced by a stepping motor which is more aligned to the use on mirrorless cameras. The good news is the pricing only increased marginally to around 950 USD/EUR both in Sony E- and L-mount.

It may come as a little surprise but the Sigma 100-400mm f/5.6-6.3 DG DN OS is actually slightly longer than the DSLR design. At longer focal lengths there isn't much you can do about the size unless you start using e.g. fresnel lenses which come which their own challenges. The build quality seems to have improved a bit specifically near the mount where Sigma has replaced the plastic rear tube with a metal one. The weather sealing is still rather basic with just a gasket at the mount. As usual, the lens uses an extending zoom mechanism towards longer focal lengths. Besides the zoom ring, you can also push/pull the inner tube at the front. Sigma calls this a "Dual-action" zoom mechanism. A transport lock is also available at the 100mm setting. The focus ring operates smoothly. A deep barrel-shaped hood is part of the package. 

The stepping motor used for auto-focusing is pretty fast and noiseless. You can also control the AF using a dedicated AFL button.  The optical image stabilizer (OS) offers a claimed gain of up to 4 f-stops. As usual, the real-world efficiency will vary on a number of external factors such as your coffee level, focus distance, or simply because it's windy. Besides the standard stabilization mode, there's also a dedicated mode for panning.

Optical construction22 elements in 16 groups, with 1x FLD, 4x SLDs elements
Number of aperture blades9 (rounded)
min. focus distance112(W)-160(T)cm (max magnification 1:4.1)
Filter sizeφ67mm/td>
Hoodbarrel-shaped, bayonet mount, supplied
Other featurestransport lock, Dual action zooming, OSS, optional tripod mount, AFL button

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