I was sent this lens to try out . I currently use the Sony 100-400, which is seen as the best lens in this segment abeit at a price well over £2000. The Sigma is far cheaper and retails in the U.K. for £899. Not everyone wants to pay or can’t pay £2000 plus for the Sony so it’s nice to see that Sigma can offer an alternative in Sony E fitting.
The lens is well built and just like the Sony, the actual length of the lens will increase as you zoom out. The Sigma is slightly smaller and thinner then the Sony and when zoomed out there is very little difference length wise. The Sigma is also around 250 grams lighter. With the Sigma you can either turn the zoom ring or push and pull to zoom in and out. The Sony is conventional and you need to turn the zoom ring in and out.
Both lenses are weather sealed and there is a rubber gasket fitted around the mount of the Sigma.
The Sony has a fitted tripod socket which isnt ARCA Swiss compatible so you either need an adapter plate or a replacement foot like the one from Kirk enterprises. The Sigma has no tripod socket but it can be bought. (Sigma TS-111) I think it should have been part of the lens, so now you need to buy it at extra cost!
Feature wise both lenses kind of offer the same features. Sigma offers a lens lock whereas the Sony offers a tension ring. The Sony manual focus ring sits at the front of the lens whereas the Sigma sits at the back. I find the resistance and smoothness of the focus ring of the Sony better but that’s just personal taste.
The minimum focus distance is better with the Sony thus allows for better use for butterfly and other small critter photography (higher magnification)( Sony 0.98 cm Sigma 112cm)
The Sigma is also 1/3 of a stop slower then the Sony hence why I think the lens is somewhat slimmer and lighter.
The Sigma has a Focus AF/MF switch. Followed by a focus limiter with 3 settings to increase focus speed. An AFL button which allows to cancel autofocus when AF is engaged. Finally it has an OS switch which allows to select the appropriate optical stabiliser mode.
The lens hood clicks in firmly and does not have the “push” release button like the Sony.
Sigma announced 2 new converters, TC1411 and TC2011 but currently only available for the full frame Panasonic bodies. If these converters do get released for Sony E I would personally use converters only in decent light situations as the Sigma is rather slow.
Its a shame that currently, the Sigma USB dock is not available for the Sony mount . The dock would alllow for fine adjustment in parameters like focus speed, focus limiter, OS settings and firmware updates. Hopefully it will be released at some point as it would definitely benefit this lens.
All in all i think, feature wise, the Sigma 100-400mm lens is on the money . It’s well built and personally I like the design of the lens.
The Sigma is a tad slower then the Sony. At 100mm its F5.0, at 135mm it is F5.6 and at 285 it changes to F6.3
AF: in my my view the AF is very responsive, perhaps a tiny bit slower then the 100-400 Sony but there is very little in between the 2 lenses. The Sigma’s operation is quiet. Funny enough i like to handhold the Sigma more then the Sony, probably due to the slimmer design, which means it easier to wrap your hand around the lens.
Another point is that the AFL button on the lens can be programmed for any other function that the Sony bodies offer! I have set up this button for AF/MF control hold.
Images look crisp, lots of details and a nice contrast. I honestly can’t fault the lens. To my eye the images taken with the Sigma are a little bit more contrasty than with the Sony.
I took the Sigma 100-400 to the park to take some real images. Needless to say: Bushy park is not rated for its birds and wild animals (unless you think park deer are really wild!) The park was very busy, as could be expected! So the images are not fantastic but perhaps it gives an impression of the lens. A flying heron is not a real test for the AF as its a relative slow flyer but no ducks were up in the air! What i found is that the AF is a bit slower then the Sony 100-400 and at times it simply looses focus (but not often). Good optics, decent AF. Lack of tripod socket a miss (its an optional buy) and minimum focus distance. All in all i think this is a fine lens and is a good alternative for the Sony 100-400. Warranty of the 2 lens is 2 years, lighter than the Sony, weather sealed, nice slim design and responsive . Some might find the lens a bit slow at the long end but other then that: there is very little NOT to like about the Sigma. Recommended!
Below you will find 100 pct test/crop images at 100 ISO . The lens was set at 100-135-200-300 and 400mm, handheld. Light conditions were good. No post processing.
Sigma 100-400mm F5-F6.3 DG DN OS positives:
Good optical performance/Price
Dust and splash proof, well built, slim design
Good AF performance
250 grams lighter then the Sony
Sigma 100-400mm F5-F6.3 DG DN OS negatives
No USB Hub for Sony E available
Tripod collar will cost extra
Manual focus ring not as smooth as Sony
Wish it was 5.6 all the way
Minimum focus distance not as good as Sony