Processing:
By design, it looks like a high-quality Zeiss. Would not the Sigma lettering as one would confuse it with a determined. How to but the saying goes, it is the inner values that count. The build quality is great, the 18-35mm f / 1.8 looks good and feels valuable and need the comparison with expensive Canon L and Nikkor shy on any account. In addition to lots of glass Sigma has in this lens set mainly on metal processing and precision, what one sees especially at the terminal, the zoom and the focus ring and feels. Both rings run neither too stiff nor too soft, but just right, as you would expect from a lens of the highest class also. The latter does not rotate with the use of the auto focus. Another plus is the provided quiver and lens hood. The latter is indeed plastic, but when you consider that Gelis must be bought at increasingly CaNikon great expense, you can not help but to praise Sigma for this generosity.
Optical performance:
When I look at the first photos taken at maximum aperture on my screen, I could hardly believe that a zoom can be as sharp. Most of the other standard zooms are significantly worse at full aperture and do not offer as f / 1.8 but f / 2.8 at. So 1.33 aperture less light intensity. The Sigma is not just the brightest zoom for DSLRs, it's also one of the most outspoken. In the short time in which I did it, I could not see any picture only serious weakness. Whether it's photos, taken with 18mm, 24mm, 35mm, or somewhere in between, look at that image quality is always at the level of a prime lens with f / 1.8, but often better. Therefore, I have christened the 18-35mm f / 1.8 prime lenses killer, because to be honest, since there is this push, it makes no sense to buy prime lenses with f / 1.8 betw. 18mm and 35mm. You could buy a 30mm or 35mm f / 1.4 might be wondering if you absolutely need the extra light intensity, but the f / 1.8 FBWs were made obsolete by this zoom. Vignetting and distortion are all in the green zone. Like another reviewer, I too could sometimes discover at wide angle CA at the edges. Most in strong contrast, such as in tree branches against a cloudy sky. But they were rather weak and could be overcome with some wonderful EBV. No reason to worry.
Autofocus and price:
There is not much to say to autofocus, because these works quickly and reliably. Not Formula 1 fast, but faster than that of most lenses. The price I have to mention here separately, because I was also a man who even before the price was announced, has speculated by more than 1,000. The current street price, which hovers around 700, is more than fair. As I said, I myself expected that a revolutionary lens as the 18-35mm f / 1.8, many more costs.
Conclusion:
The Sigma 18-35mm f / 1.8 is mMn one of the most interesting and most ambitious of the optical design her lenses in recent years. It's not just the brightest zoom for DSLRs, but also one of the sharpest zoom at all. It is so sharp and free of optical defects that equal most fixed focal length, but is superior to many. The price for this service more than fair. Would it be a Canon or Nikon lens, it would cost with probability bordering on certainty more than double. The only negatives are the weight / size and the lack of stability, said more than bleating at a high level is. Anyone who is not a change of lazy electric eel, the Sigma should look closer. Strong buy recommendation!
