9 out of 10 points and recommendedsharp, lightweight, f2.8no stabilization, build quality, noisy old autofocus motor
I have the Promaster branded version, bought used in 2010, other than the branding and a different zoom ring texture it's simply a first generation Tamron. F/2.8 is fuzzy in the far extreme corners, pretty good on the edges, and the centre is almost as sharp as at f8. F8 pretty nearly wrings out every pixel of my 7D. Bokeh can get a bit harsh with high contrast backgrounds.reviewed July 29th, 2017
Sometimes I wish the lens was stabilized, I wish it wasn't in a plastic fantastic body (the front element got knocked and came slightly loose once so I had to pry off the cosmetic front piece of plastic to be able to tighten up the screws), and I wish it had fancy autofocus. But I've used this lens in dim museums plenty of times without stabilization, the plastic body is light, and the noise doesn't bother me much and the AF works fine.
So I've had this cheap little zoom for a long time, even though sometimes I pine for something fancier I just always come back to loving my sharp little zoom.
9 out of 10 points and recommendedfocal length, full time manual focus, good image quality stopped down, nice build qualitybad wide open
Ultrawide is my favourite range, it's so much fun, but it's also really hard to design lenses for. So, ultrawide comes with optical issues unless budget is thrown out the window, one thing the sigma 10-20 f4-5.6 is most known for is it's whacky distortion profile (but it's one click to turn on lens correction and get rid of it, don't worry about it). Wide open it's soft, vignettes a lot, and underexposes, generally max aperture should just be avoided whenever possible. Stop 'er down and she's pretty sharp.reviewed July 29th, 2017
For some reason with this lens the focus is not super accurate on my 7D, but on the other hand you don't really need to focus at 10mm anyways especially if you're shooting at like F10.