I bought into the Nikon system because of the 'variety' of quality 35mm lenses they produce. I have been using Nikon cameras and Nikkor lenses since the early seventies, and have never been disappointed their quality, or performance. If I shoot a bad photo, it's my technique that's at fault, not the lenses I use. Third party lenses may be just as good, I'll never know, because all my lenses are Nikkor, and that's all I'll ever use on my Nikon cameras.
