There will be little difference on the night before or after a full moon as far as light. This is assuming there is no cloud cover.One probably could get by most areas with the light of the full moon but there must be dark shadowy areas that will not be a recipient of the full moon light due to trees and Mtn ridges.A lot would depend on the time of night and where you are on the trail. I would definately have a headlamp close by no matter what.Just because there is a full moon which can be counted on doesn't mean it will be clear of clouds which cannot be counted on.
