Why I have chosen for the Sigma?
The starting point:
I was looking for an ultra wide angle for landscapes, which has good image quality on my Nikon D600. After much research in various forums and magazines three lenses were shortlisted:
Nikon 16-35mm VR 4, Nikon 14-24mm 2.8 and the Sigma 12-24 mm.
I tested all three lenses thoroughly at home and with a friend who owns the 16-35 mm. It quickly became clear to me that I would like to take advantage of the ultra wide-angle and therefore the well 16-35mm Nikon lens to use to retire despite the possibility of filters. (Due to the digital processing of RAW files, filters are no longer necessary. This saves a lot of money and time!) Now I had to choose ONLY between the excellent Nikon 14-24mm lens and the Sigma.
In use, the very serious and front-heavy Nikon lens is used to. In dark rooms, the maximum aperture of 2.8 is helpful, but the edges of the image are considerably blurred. It will only fit into my photo backpack or mounted with camera in your pocket. It is then only space for a small 50 mm lens. Those who want to be mobile and climbing mountains, which is so determined to sweat. After extended operation, I got along well with the lens clear, but the transition to the Sigma the weight difference is again very clear. The Sigma is by and 4,5 maximum aperture much smaller and more manageable. It fits as a second lens in my bag and I can carry around a large zoom range comfortable with me. So great plus for Sigma!
Now for the imaging performance:
Sharpness:
I have received numerous test photos. (Part landscape, part of a photo test card, always from the tripod with mirror lock-up and focus on the image sensor)
In general, I can say that the Nikon has a larger optical performance and superior "visible" especially in the Sigma 24 mm. However, only the zoom into the pictures ...
At 14mm the Sigma has the edge because it is sharper in the corners. The large maximum aperture of Nikon goes through the necessary stopping down lost again and this advantage is wasted. Clear the Sigma is at 14mm is not the bottom limit, the Nikon already. At 12 mm, the corners are then at Sigma significantly blurred. But what is then for an overwhelming picture angle !!! Since my pixels in the corners regardless. And who zooms been constantly in the corners of the images if he considers a great motive ??? When I use the photos with Lightroom editing are barely visible differences between the two lenses. My impression is that Nikon 16mm to 24mm and is better at Sigma 14mm (RAW formats in direct comparison in the second window in Lightroom) on the test patterns with the test card, the differences are more noticeable than in landscape shots.
Distortion: A clear plus for Sigma! Nikon has a strong pincushion distortion which is much lower when Sigma at 14 mm.
Vignette: Plus for Nikon
Chromatic aberration: slight plus for Nikon
Conclusion: They're both very good lenses. The Nikon has better imaging performance, in which case only for me is the focus of concern since all others can be corrected very well in Lightroom. In use, I see the clear advantages of Sigma. (Even the lens cap is attached here better and is also partly made of metal!) Who ever wants to make 1.50m large prints of his pictures, which should not shy away from the significant price difference and access to Nikon. Anyone like me who enjoys great Lanschaftsaufnahmen and which from time to time produces a greater deduction, which is very well served with the Sigma and has 2mm less focal length available. For my applications, I like to take the little minus on the edge of the large decline in the weight and price into account.
Therefore clear 5 star for Sigma