Excerpt: Sony is doing some pretty loose math by calling this an f4.5 lens on an APS-C camera. If it were on a 35 mm FF camera yes it would be f4.5 Let's do the math a 210 mm lens @ f4.5 = front diameter of 46.66 mm With the crop factor you have a 315 mm equivalent. The front diameter doesn't change so divide the 315 mm lens by 46.66 and you get an f6.7 lens, not an f4.5. If you think you're going to get an f4.5 lens on an APS-C sensor, you're not. The physics don't work.
fair low end lens for someone stepping up from traditional point and shoot cameras.
21 October 2014
Summary: Overall, I was unimpressed with this lens. I recently tried out a Sony camera, and took several pictures, and the pictures from this lens seem to be washed out and blurry. That being said, I can't necessarily blame it on the lens, but it seemed to happen most when I used this lens. Otherwise, it was a fairly fast lens, and seem to be well built for a low-end consumer model.
Summary: ORIGINAL REVIEW: Do not buy this lens for a Sony NEX 6! In theory, it's just fine, and it worked fine when I received it, so I set it aside for an upcoming vacation. The first time I tried to use it in the field, though, the camera would not recognize the lens, would not focus, and would not shoot. Google the thread "sony nex 6 lens not recognized" and be warned. The lens is apparently made loose and the contacts don't connect well -- at least to the NEX 6.
Summary: Whilst it's good to have a telephoto lens in the NEX range, I haven't been wowed by the quality of the shots from this lens, as compared to the 18-55mm kit lens or the 50mm prime lens that I also have. There is a lack of detail and texture that is certainly noticeable. With that said, the lens remains sharp and is quick and reliable in its focus.
Summary: I flatter myself that I'm an "advanced amateur" photographer for over 50 years. I'm quite used to Canon DSLRs and their lenses, and to Sony E mount prime lenses. I really wanted this lens to work, because the focal ranges were exactly what I wanted. I spent many hours and hundreds of exposures trying to "learn how to use it" - but in the end, I returned it, because I could not get an acceptable percentage of "keepers" with the 55-210.
Summary: While I enjoy using this lens, it's soft at 210mm. At first I thought I had a defective copy, but the reviews seem to say this is a common issue. It's still a decent lens, but the softness does limit it's usefulness for wildlife photography.