Conclusion: This new 28mm IS USM lens is about as good as it gets, image sharpness wise on Canon SLRs. On a crop sensor (APS C) body it works out to a 44.8mm lens, in 35mm format terms. That's almost exactly what your eye sees and was once considered the "normal" focal length in 35mm photography. If you read any of the many reviews online, it out performs even the 1.8 (non IS) version, which is much older technology. CA is really low here, almost non-existent.
Pros: Fast auto-focus, Super-sharp images, low distortion for 28mm, low ca
Excerpt: I purchased this to go with my 50mm 1.4 & my 85mm 1.8. I could not decide if I wanted a 28mm fixed or a 24-70mm. I went with the 28mm. Used this for engagement photos in the mountains here in Colorado and they turned out amazing. It's very fast & light weight - great for portraits and landscapes!
Pros: Durable, Easily Interchangeable, Fast / accurate auto-focus, Lightweight, Nice Bokeh, Strong Construction
Excerpt: I prefer zoom lenses for the versatility, but when I am inside I generally do not get enough light to make my camera happy so I go to a prime. The 28mm f/2.8 IS USM is working great for that scenario. In fact this weekend I ran into that exact situation and the lens performed excellent.
Pros: Consistent Output, Easily Interchangeable, Fast / accurate auto-focus
Excerpt: I purchased this lens for an upcoming trip to Ireland. I wanted a relatively wide angle lens as an alternative to the EF 28-105 L lens I usually use for travel. This lens is very clear, fast (f2.8), has IS, is light, and not a budget breaker. Easy to carry around without fatigue.
Pros: Fast / accurate auto-focus, Lightweight, Nice Bokeh
Summary: I hesitated about buying this lens as I already have a 28mm lens. However, the IS makes a huge difference in street shooting. In this scenario you typically have varying light, and you want max depth of field, so the speed of the lens is not as important as the IS is. I love the lens, results are sharp, no distortion.
Summary: I have the older 24mm f2.8 non USM. This one is clearly superior optically (sharper, lower distortion, less aberration and colors are far better). The difference is more pronounced at night where this lens shines with my 6D. Color rendition is warmer than the old lens. Even though I have the 24-70 II lens, this one is just as good at a fraction of the size and weight, therefore, if you like travel and size / weight is a concern, this lens is definitely worth it.
With this lens, my best photos ever - but be sure you use IS properly
12 January 2014
Summary: The combination of a newly designed prime lens with full frame coverage plus Image Stabilization gives amazing optical performance, especially when only the central portion is used on a half frame camera, producing some of the sharpest handheld photos I have ever captured, period. It's also light and small. I used it on my tiny Canon SL1 body and the results are fantastic for general photography with an equivalent focal length about 45mm.
Summary: This lens looks and feels very pretty and sturdy. I am not a professional photographer, however, have used it with canon 7D at night and got wonderful results. During daytime, with 7D, this lens produced crisp pictures with accurate colors. I have also posted picture of an iPhone just to show how the bokeh looks at f/2.8. If you want to see how a camera will look with this camera, I have uploaded a picture of 7D with this lens and a hood mounted.