Reviews Sigma 10-20mm f4-5,6 EX DC HSM (for Nikon)
Design
My first impression is that this Sigma is very solid and well designed. The outer shell is made from hardened plastic which feels very strong and solid. The zoom and focus rings are made from dense rubber with grip indents. When mounted, the focus ring is located furthest away from the camera body, making the zoom ring closest. Zoom markings indicate 10, 12, 14, 17 and 20 mm.
Zooming is a little bit on the stiff side but this is not a real issue because of the small amount of zoom of this lens (10-20 mm). The focus ring on the other hand is very smooth; there is quite some contrast between the zoom and focus rings.
The filter thread size is 77 mm, which is the easiest size to buy filters for. Especially if you consider that 77 mm is found on most of the professional grade lenses and the EX Sigma design is no exception.
With the plastic lens hood mounted it can be very difficult to remove the supplied lens cap. The rear cap also has problems. Nikon rear caps have three entry points while Sigma rear caps only has one. So putting the rear cap on in the field can be very fidgety. Sigma rear and front caps are of a poor design and I hope Sigma updates this with their newer range of lenses.
Performance
Focusing is extremely quiet and lightning fast, thanks to the HSM system. I have never had a problem so far when it comes to locking focus in auto focus mode, even in darker scenes. This is also thanks to my Nikon D2H, on a non-professional body however AF performance might be somewhat slower.
Saturation is very pleasant; colours are well rendered and accurate. I wish I could say that the contrast is special like my Nikon 28-70 2,8 but it's not.
Sharpness is very good, although corners are on the soft side. Peak sharpness for me was around 12mm at f8. As said, corner softness is noticeable at the wide end but since apertures smaller than f8 will result in very sharp corner to corner images, this should pose no problem when shooting landscapes.
Viignetting is very noticeable wide open. This is typical of ultra-wide lenses but can be controlled by stopping down. Vignetting can also be controlled very easily with Photoshop or Nikon Capture. I accepted that there would be some vignetting before I even shot one image with this lens and although it was present it was not as bad as I thought it would be.
Chromatic aberrations are more of a issue to me as I prefer to shoot landscapes which is a breeding ground for chromatic aberration. Unfortunately for me CA was present at 10 mm and very slightly present at 20 mm. Luckily it was not a major problem and when I stopped down to f11 it was completely gone, so my landscapes are safe with this lens.
Barrel distortion on the wide end and pin cushion distortion on the long end was present. In my tests barrel distortion was extreme and pin cushion was very slight. No focal length is safe; some kind of distortion is visible at every focal length. If you shoot brick walls for a living don't buy this lens. For the rest of us, distortion will not be very noticeable.
A fun feature about this lens is that it can focus very close (24 cm), making it a very fun and dynamic lens to use.
Conclusion
For less than 500 euro you can’t get much better than this. The lens is both sharp and offers more than acceptable contrast and saturation. Chromatic aberration could be an issue for those who choose to shoot wide open most of the time. Stopping down will control CA somewhat. The same can be said about vignetting.
Its professional build quality and compact size makes this lens a real winner. Be sure to replace the front and rear lens caps with Nikon original caps if you choose to buy this lens.
Links
Sigma website, sigma also has many alternatives to the 10-20 mm like the 12-24 mm.
Kamera-express dutch photo equipment store with very competitive prices. They stock Sigma products.
