Colin,
The Nikon 15 mm 3.5 is a great lens and a lot of fun to shoot with. But,
IMHO I would go with the 18mm. The 15 is very large and has an element that
is prone to being scraped and smudged (think front element similar to the
16mm except twice the size.) The 15 is very expensive and I believe
(correct me if I'm wrong) the 18 is cheaper in price. Also, the 15 comes
only in an AIS mount and the 18 comes in the AF-D. The image quality of the
15 is good but it tends to fall off some at the edges. If you really need
to go wide, an alternative to the 15mm is the 16mm 2.8. The 16mm can take
practically distortion free images if you are careful where you line the
horizon up. The 16 comes in AF-D and is only about $550-600. You could
probably pick up the 18mm and 16mm for the price of the 15mm.
hope this helps,
________________________________________________________________________________
Bob Croslin
Staff Photojournalist, The Tampa Tribune
[EMAIL PROTECTED]
http://home1.gte.net/bcroslin/index.html