use the SEL50f1.8 on my NEX-5N. The workmanship is very good and the materials appear to be of high quality. My motivation for buying this lens was primarily the high light intensity and, according to all tests, the very good imaging performance. I was not disappointed in either respect. Even with an open aperture, the edge sharpness is much better than with the (stopped down) 18-55mm kit zoom. From approx. aperture 2.8, the 50mm lens then produces excellent images over the entire range! As with the kit zoom, the built-in optical stabilizer enables relatively long exposure times, even without a tripod. 1/10s to 1/20s are handheld with no problem, or even less if you have a steady hand. Up to now it has practically never been necessary to set the ISO higher than 3200, which makes the NEX a very good "available light" camera. The exposure potential is also very good at an aperture of 1.8 and the bokeh is very pleasant. The focus motor works relatively quickly and quietly, but the aperture blades may be audible when focusing because the aperture is opened. In my opinion, the autofocus is a tiny bit slower than with the kit zoom, but it is fast enough for my needs and, above all, very precise. Manual focus (steer by wire) is also possible and works very well due to the smoothly running focus ring. For videos, however, I find the "crank travel" when focusing manually to be a bit too long. Very precise adjustment is possible for this. If you are looking for a sharp, fast fixed focal length with autofocus, you will have a lot of fun with the SEL50f1.8. In my opinion, value for money is very good.