To clarify my advice. As a general rule, I like to illuminate objects in ways that convey nighttime - meaning, areas of dark and light that mimic a single light source (like the moon) with little or no ambient lighting. This means that parts of a tree would not be illuminated. Illuminating a tree trunk from all sides is essentially re-creating day-time lighting. Illuminating it so that the front or a side is dark looks much more natural. Choosing which side of the trunk to leave dark is a creative challange - especially when it will be viewed from many angles. Keep in mind that the worst angle of viewing is the angle that shows the trunk fully illuminated. Also note, that for projects like this (where many trees will be viewed in a single lighting scene), all the trees should be lit consistantly (shadowed sides the same). All lighting should make some sort of visual sense. Regarding bullets vs. wells - many reasons to choose bullets - easy to move as the tree grows, no problems with stuff acummulating on the lens, and no ants in the fixtures.