Because of the dim light in the canyon, and the need for a high f-stop to maximize depth of field, exposure times generally varied between 1 and 30 seconds. A very stiff tripod/ballhead are definitely helpful here! Also, I enabled the timer function and mirror-lockup to minimize vibration and enabled the long exposure noise reduction option of the D30. And lastly, with multi-second exposure time, it was often challenging to keep people from walking through your picture, or use a flash that would ruin it. Still, most people were polite and accommodating. Canon 28-135 at 28 mm, ISO 100, f/22, 4 seconds.