There was an entire response lost between your 3:48 am and my 421am reponse. Here it is:
David,
No I've never used the fish eye, just don't have a need for it. The 12mm setting on the lens is adequate for me in just about any digital situation. I find that 12mm is actually too wide most of the time for my taste and I seem to use it primarily in the 14-18mm range. But, I have used it at 12mm as well, many times. At 24 mm this lens shines. Pincushion and barrel distortion are NOT detectable by the eye. Perspective distortion can be (leaning over backwards) nearly eliminated if and only if, you keep the back perpendicular with your subject, such as a wall or building and you are not too close to your subject.
I've found while using this lens for 9 months now, that when I put it on the camera, it gives you all you need when your minds' eye says it's time for a wide angle lens. The only real drawback that I have seen with it, is the low light, auto focus capability. It will focus behind your subject 40% of the time on the D100 and only about 20% on the D2H. So you need to either use distance and f-stop on manual focus ~or~ override the focus, which the lens is designed for, and which works nicely. In normal daylight situations, the focus is nearly instant especially with the D2H and F5, only very slightly slower on the D100. So on your D70, it will most more than likely seem and be plenty fast.
I use my gear nearly every day, and it gets the use and sometimes inadvertent abuse that can be expected. I've found that the dust resistance is very good and will not be a issue under amateur/advanced amateur use.
I think this is THE best wide zoom Nikon has made to date. It's real performer.
Regards,
Bo