- Because the old 17-35 is no longer good enough for sensors like the D800 that are exceptionally accurate;
- Because the duo 14-24 and 24-70 cost an arm and forces to change just aim at the wrong time;
- Because with 36 megapixels, can I crop my photos and turn a photograph taken 35 photo taken at 70 and still retain 18 million pixels;
- Because quality ED glass (low dispersion) is truly extraordinary;
- Because 16-35 is a bit wider, OK, stabilized, OK, but much more expensive and much, much heavier. And that stabilization, anyway, on a 20 mm focal length, used very little, especially since it stabilizes the movements of the photographer, not the movements of the subject (eg children who move will 1/40 still unclear, even with a stabilizer), and anyway, you can mount ISO to gain pause ..
