I've been having trouble getting used to this lens and I don't know why. It's a small lens with great build quality. Focusing is smooth and the aperture ring is very light. I've got other legacy lenses in the 50 range and I don't have a problem with them. Maybe I nees dome time with this lens. I haven't got many images that I have kept from this lens but this is one that I like. Focus is where I wanted it to focus and the colours and contrast are ok. Again, I may need to try this out on the Nex-5N.