I was trying to take a picture of a Christmas tree with decorating lights on, in a dark room, mostly lighted by a large screen TV (that the picture brightness varies as the TV goes). The Nex7 with Sony SEL 50mm 1.8 lens could not do proper auto focus, in about 8 out of 10 pictures. The Nxx7 with Sony SEL 18-200 full size 67mm filter lens performed good auto focus in about 6 out of 10 pictures. Nikon D700 and D300S, and D200, taking the same picture, performed 100 % perfect focus instant auto focus without any hesitation. Surprisingly the bright 50/1.8 Sony lens auto focus was very poor. The bright lens was suppose to be better suitable for low light condition, but it could not do auto focus, practically at all. The picture attached below shows how NEX7 with SEL 50/1.8 lens locks up focus and refuses to do it right. It was necessary to refocus on something bright, e.g. TV, and the focus resumed working, otherwise the locked focus allowed taking the funny picture, then next picture possibly would have a better chance to focus, but really 8 out of 10 were back into this focus lock. I wonder if the new focus improvement in the NEX5R and NEX6 would provide better auto focus ?