Summary: I tried this lens in both 19mm and 30mm versions. Also tried the EX DN and DN ART versions. Both are good lenses. I prefer the look of the ART version. I found the 30mm a little to narrow for a walk-around lens... the 19mm was more versatile. On their own both lenses are very good and in the price range they have no equal. However, I found them performing no better than the Panasonic 14-42mm on my panasonic GX1. Keep in mind the crop factor on GX1 is 2X.
Summary: Beautiful lens with great quality but I never seem to use it. First of all it's an APS-C lens on a MFT mount so it is oversized. I also have never been a fan of so-called normal lenses since it rarely fits the way I see the scene. To me a 12mm - 15mm (24-30 equivalent angle of view) really feels more natural and then I want to jump to 40mm (80 equiv. or greater angle of view) that represents when I mentally focus on a subject.
Excerpt: The 19mm on a micro four thirds is about 38mm field of view in 35mm terms. Similar to the 35 lens I used on my Leica back in the film days. A great lens for most purposes. This lens focuses close, real close. Works fine and takes great images. The smooth focus ring is strange but since I don't use it much it is a non issue. Overall it is a nice handy unit.
Summary: First, I am not an expert in photography by any means! I bought this item for my Sony NEX-3N because prior to that I only had Sony's 50mm f1.8 lens. The 50mm is a great fast lens especially for low light situations but I found that using this lens was inconvenient many times such as when I had to take a wide picture of say a group of kids, I had to step very far back. Even taking a picture of my car required me to step back quite a ways.
One of the best lenses for the money glad I bought it
13 April 2014
Summary: I have this for my Sony NEX to replace the kit lens and it is great. Color and contrast, C/A and vignetting control are superb compared to the kit lens. The only thing is that it is a pretty long lens. Plus although it resolves much more detail than the kit 16-50mm lens it's only 5-15% sharper. Maybe I got a soft copy because this lens should be even sharper for a prime but it's not as bad as the kit lens.
Excerpt: I wanted a prime at a good general-purpose focal length. It was between this and the panasonic 20mm f1.7, but the latter cost much more. I saw the Sigma used here at Adorama and got it. Very pleased with the service and product. The lens arrived a couple days early and is in excellent condition. Not sure the image quality is that much better than my kit zoom, at 19mm, but maybe a little.
Summary: It took me a little while to get used to the chattering sound it makes when the camera is turned off but as long as I know that's normal and not a defect I can live with it. I haven't had a chance to take too many photos with it but the few I have taken look great. I took a beautiful sunset photo with it yesterday which made me decide to keep it.