We use a Kase Wolverine 3 stop (.9) Graduated ND filter for sunrise and sunset landscapes. We prefer the Kase .9 because we have found that three stops provides the dynamic range adjustment we need in sunrise and sunset landscapes. There are lighter and darker filters available singly or in kits of three. The 2, 3, and 4 stop Graduated ND filters are best for this type of landscape photography. A key consideration in choosing a filter is obtaining one of good quality. There are a number of quality brands available such as Kase, Tiffen, Benro, Breakthrough or Lee depending on your budget. Please email info@photojeepers.com if you have any more questions. We’re happy to help you plan for your trip to Arches!