Originally Posted by
D1andonlyDman
Well, please let me know which ones you mean, because all of the following have serious barrel distortion issues at 18mm:
18-55mm, 18-55mm VR, 18-70mm, 18-105mm VR, 18-135mm, 16-85mm VR (the best of a sorry bunch at 18mm), and 18-200mm VR (more expensive, but still has the aforementioned problem in abundance).
I can't seem to find any other Nikon AF-S zooms besides these that can be bought for under about $800, and none of those above pass muster for delivering straight, undistorted lines at 18mm.
The only Nikkors that do are the 12-24, the 18-35 non-AF-s, the 17-35mm f2.8, and the 17-55mm f2.8, and only the non-AF-s 18-35mm is within the budgets of many D40/D60 owners - but, again, with no autofocus on those cameras.
If, on the other hand, you feel that any or all of the lenses I listed in the first group above are perfectly good at 18mm, then we'll simply need to agree that you're a lot less critical about your wide angles than I am. Because they all suffer badly from linear distortion at 18mm. I need a wide angle that renders straight lines as straight, not as arcs.
Neither the 12-24 nor the 18-35 render "straight lines" at 18mm. They both have visible distortion.
Barrel distortion is an as-of-yet unavoidable problem with extreme wide-angle lenses, particularly wide-angle zooms.
Even my $1700 14-24 f/2.8 [which is currently the best lens of it’s kind regardless of brand] has
some distortion at 14-16mm.
The Nikkor 12-24 at 12mm has mustache or complex distortion which is very difficult to correct. From about 15-18 it has simple barrel distortion which is easy to correct but there none-the-less. The truth is that in absolute terms that lens really doesn't shine until about 20-24 and, IMHO is significantly over-priced for a lens with consumer-grade build and an f/4 maximum aperture.
The 18-35 is another mediocre lens that also has visable barrel distortion in the 18-22mm range and it is woefully soft in the corners until f/8, it also flares like a SOB and has problems with chromatic aberations [color fringing] to boot.