I think the rumored AFS 16-80/2.8-3.5 is a more interesting lens to most, not least because it is more affordable. This is obviously an upgrade to the current 16-85/3.5-5.6 VR. The lens looks remarkable in a number of areas. Compared to the current 16-85 it is half a stop faster at the wide end, and one and a half stops faster at the long end. It's almost a constant aperture zoom, dropping just a shade over 1/2 stop at the long end. That's a huge improvement. The new lens appears to be very compact, judging from the pictures on nikonrumors, the filter size is 67mm, the same size as the older version. That is amazing considering how much faster it is than the old version.
In some ways it parallels the upgrade of the older variable aperture 24-120/3.5-5.6 to the current 24-120/4, although in this case it's not quite a constant aperture zoom. The faster aperture of the 16-80 means the DOF and ability to isolate subjects is almost the same as the FX equivalent.
The rumors also state it has an electronic diaphram, which is the first time we see this feature on a "normal" lens. So far it has been restricted to tilt-shift lenses and super telephotos. A sign of things to come.
This lens could also be considered an replacement for the DX 17-55/2.8. In exchange for dropping just a half stop you get:
- VR, which largely compensates for the slower aperture at the long end
- zooms wider to 16mm, giving a true 24mm equivalent angle of view
- zooms significantly further
- nano coat means it should be more resistant to flare - one of the weak points of the 17-55
- fluorine coating
- it's also much smaller
It remains to be seen whether the optical or build quality is as good, from the appearance the build looks more mid-range rather than professional level, but overall it seems to be a very promising lens for the DX user.