Judging by how differently NEX-6 and NEX-5N handle the new pancake SEL-P1650 zoom lens (plenty of references on the Internet), it appears that the inputs to the in-camera correction (CA, vignetting and light fall-off) algorithm are not stored within the lens, and so to work properly with the lens, the camera's firmware needs to be updated. NEX-6 handles the lens properly, while even the "corrected" JPEGs out of the 5N retain pretty strong vignetting and geometric distortion at wide angle. Moreover, NEX-6 seems to crop the image, so what SEL-P1650 presents as the widest angle to NEX-5N is most probably wider than 16. Basically, NEX-5N doesn't know how to work with this lens.
It seems that Sony is pretty diligent about updating the firmware of Alpha cameras to include the auto-compensation profiles for the new lenses. Why isn't it the case with the NEX line? In the one year since the 5N has been available, not a single new lens has been added to its firmware. I have two arguments for why having timely updates is more important for the NEX line than for the Alphas:
(1) The number of E-mount lenses is still, frankly speaking, extremely limited, and Sony keeps extending the deadlines for the roadmap for the new lenses. Last thing you want to do in this situation is to send the message to your potential customers is that when they are buying a new NEX camera, they should make sure that they are content with the very limited number of lenses currently availble, because the camera will not support the upcoming lenses properly (shooting NEX-5N with SEL-P1650 is a case in point)
(2) There is larger percentage of NEX users, compared with the Alpha line, who do not post-process RAW files and rely on shooting JPEGs only. For these guys, having in-camera compensation working properly is essential, especially for challenging designs like the pancake SEL-P1650, and I suspect it's going to be the same story for the upcoming wide-angle 10-18.
