I'm thinking of trying to expand my photographic horizons in buying an ultra-wide angle lens (probably the 10-24 DX). I've recently dipped my toe in these waters since upgrading from an 18-70 to a 16-85 zoom. My main types of photography to date have been travel, landscape, urban, and macro, with a bit of portrait thrown in for good measure. My current kit consists of the 16-85, a 60/2.8, a 70-210/4-5.6 (all autofocus), a 50/1.4 AIS, a 35/2 AIS, and a Flektogon 50/4. I'm pretty happy with the first two and the AIS ones, and not so happy with the 70-210, though AIS lenses are admittedly cumbersome to use on my D70, especially for quick-reaction shooting. Ultra-wides are expensive, so I'd like to know that I can 'see' properly how to use one (or at least learn to) before buying. I'm sure someone will suggest renting the lens first; I do intend to do that. But having rented the lens for a day, where should I take it? What should I shoot? What should I be trying in terms of composition? What else should I keep in mind?