Two full measurement based test, that correlate corroborate each-other in the main One review I posted the link to days ago. http://slrgear.com/reviews/showproduct.php?product=1609 Here is a Lenstip review posted today http://www.lenstip.com/374.1-Lens_review-Sigma_A_18-35_mm_f_1.8_DC_HSM_.html The summary Pros: solid and stylish casing, simply brillant image quality in the frame centre, very good image quality on the edge of the frame, sensibly corrected chromatic aberration, negligible spherical aberration, moderate distortion for a zoom lens, slight astigmatism, silent and accurate autofocus, rich accessory kit, good price to ability and quality ratio. Cons: weak work against bright light. You should congratulate the Sigma Corporation and their optics specialists for two reasons. Firstly for their courage – they attempted to produce an instrument no other company had tried to construct before. Such a situation a lot can be forgiven so their product didn’t have to be outstanding. Still it is obvious Sigma wasn’t contended with half measures; not only they manufactured a unique instrument but also made it optically excellent in many categories. What’s important, I am sure there would be those willing to pay 4,000 – 5,000 PLN for such a lens and Sigma, taking into account the lack of competitors, could demand easily such an amount of money; however the company didn’t decide to follow that strategy and suggested a price which is within the reach of many amateur photographers. That’s why I don’t doubt that, like the Sigma 35 mm f/1.4 EX HSM, the 18-35 mm f/1.8 model won’t stay long on the shop shelves. Despite the slip-up during the work against bright light, taking into account all the achievements of the Sigma and its price we don’t doubt it deserves the badge below. Congratulations! Some of these results were better than separate primes like the Nikon 35mm f1.8 known as a great lens for the money. My takeaway is that this is one sharp fast AF lens.