I use it in the studio, it gives good sharpness from about 40mm, there are a couple of examples on my website p=265 then it would be 17-40 4.0 of the L series, for 30 thousand). Has some pros: Unlike 18-55, there is already GLASS, because this is a zoom lens, it can be both wide-angle and telephoto. Cons below: Overpriced for China, a bit dark, Not sharp at short focal lengths.
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