Summary: It's a fairly nifty lens. After using it for a day I was able to figure out how to get any shot I needed. I wish the minimal focal distance was shorter, but it's not so bad that I could complain (after all this isn't exactly a macro lens). I'm coming from using the Sony SEL50f1.8, and that one is certainly a superior lens, but only if you can live with its very narrow field of view.
Excerpt: I bought Sigma's 60mm f/2.8 DN to use with my Olympus E-M10. The results from the 60mm were excellent, so when the 30mm f2.8 and the 19mm f/2.8 went on sale, I ordered both. The 30mm has not disappointed and I can't believe Sigma is selling this lens so cheaply. The images from the 30mm are very sharp and have excellent image quality.
Pros: Consistent Output, Durable, Easily Interchangeable, Fast / accurate auto-focus, Lightweight
Summary: This lens is great! The images are sharp and the bokeh is smooth. It has a quality metal body that is finished nicely that doesn't keep fingerprints. Though, the metal finish is a bit slick and I would prefer a knurled or geometric surface to the slick one. The smooth rotating focus ring more than makes up for that slick surface, though. It is ideal for manual focusing when shooting video. And, the fit onto the MFT body (a GX1 in my case) is tight with no wobble.
Excerpt: I use it with Sony a6000. This lens is much sharper and faster than the standard 16-50mm that comes with the 6000 as a kit. It certainly comes closer to exploiting the real possibilities of the a6000 than the kit lens. It may not be the best lens available, but considering the price, it is a very good deal. It makes a disconcerting rattling noise if you shake it (gently) or when you turn the camera on, but the auto-focus works without fail.
Pros: Consistent Output, Easily Interchangeable, Fast / accurate auto-focus, Lightweight, Nice Bokeh
Summary: Things you need to know: - Aperture looks really small but at f2.8 it gives you a decent depth of field. - Good starter lens for those who just started photography. I usually use this as a indoor portrait lens - Cheap, so don't expect amazing DOF or anything, but it's like $200 and you'll get better photos than you would with your kit lens. - Images came out pretty sharp so I am happy with this purchase.
Excerpt: Have not used the lens a lot but by my informal tests, shooting pics of my cats, the lens is sharp at most f stops. From 3.5 to f8 it's very sharp. I can't comment on the manual focus as at this point in my life the auto focus is better than I am.
Excerpt: Purchased this Sigma with my Sony A6000 and was impressed with it's look and performance. It's a bit on the slow side, but looks and feels perfect on the A6K. The results are very good too. I don't think you can beat the performance /cost ratio. My only beef is that it doesn't allow you to use all the auto focus tracking on the A6K.
Pros: Consistent Output, Easily Interchangeable, Fast / accurate auto-focus, Lightweight