Get cloooooose-up! Read Ken Rockwell's article on how to use ultra-wide lenses. The differeces between three feet and one foot can be very monomental on lenses like the on you're buying. And keep in mind that 8.9.10.11.12.13.14.15--they seem close, but there's a LOT of difference between 8 and 10, and 12 and 15. Personally, I find the 8 to 10mm range looks very "affected" in many photos.