The Yongnuo lens showed up in the mail today, so I was anxious to take it for a quick spin. A few hand-held shots were at first dissapointing, so I yanked out my tripod and remote shutter release to put this lens through its proper paces.
What you're looking at is an array of image crops of my neighbour's van - the originals come from a Canon 40D which has a 12 megapixel sensor. These are RAW images with no post-processing, and negligible in-camera processing. Each image is labelled with the f-stop used to shoot it.
What's immediately obvious is the poor performance at the lower and top end of the f-stop range. Other reviewers state that the lens doesn't "come into its own" till f2.8, and I tend to agree. f-5.6 seems to be the sweet spot, but so is every other lens out there... I wanted this lens for its low light capabilities. Decent performance at f2.8 isn't a bad thing. I'll never use it for anything much past that; I've other zoom lenses that will suffice. As to the sharpness, I've yet to compare my lens inventory with this one... perhaps another article, or this one edited may be in the works.
So, at f2.8, this lens performs adequately, and at f1.8, you'll need some serious post processing to overcome its shortcomings. In retrospect, I shouldn't have sold my Canon f1.2. But hey, photography is back to being a hobby as opposed to a business, so who's to complain?Cheers,