Lighting assembly with adjustable light output

A lighting assembly, comprising:

• a light guide to propagate light by total internal reflection, the light guide comprising opposed major surfaces and a light input edge extending between the opposed major surfaces, the light input edge comprising light input regions, at least one of the light input regions associated with an optical modifying characteristic;
• a light source assembly comprising a light source, the light source located adjacent the light input regions, the light source and the light input regions variably positionable relative to one another to vary a location at which light is incident on the light input regions such that light emitted from the light source is selectively apportioned between the light input regions so that a characteristic of the light output from the lighting assembly is modified based on the optical modifying characteristic of the at least one of the light input regions and the relative positioning of the light source and the light input regions;
• and
• a user-manipulable adjustment mechanism coupled to one or both of the light guide and the light source and configured to adjust the positioning of the light source relative to the light input regions.