The following experiences are based on a comparison of JPEG images taken with the Tamron 18-55mm and my Sony kit zoom, I like the Tamron Duch would have replaced in most situation because of the greater Zoomberreichs. The Sony acts both in the 18mm wide angle and in the 50mm range sharper than the Tamron. In addition, the chromatic aberration of the Tamron (green and purple fringing in high-contrast image areas) were still very noticeable (especially in the 200mm range) and at the same focal length more pronounced than the Sony lens. The auto focus speed and accuracy were able to convince me, however, they are felt at least as good as the Sony lens. The already frequently mentioned problem with panoramic automatic, I can confirm that shots are blurred.
Since I bought the NEX to achieve the best possible image quality with minimum size, I now wait for the 55-210mm zoom from Sony (which then only where necessary on the NEX comes) and used in "everyday" Sony kit lens. For those that do not require the last ounce of quality and not take advantage of the panoramic automatic, the Tamron good immerdrauf lens may however well be (here I would give 4 stars, the picture quality is not bad, but at least in my case worse than that of Kit-Zoom have been).
