Charles Burchfield: Fifty Years as a Painter (DC Moore Gallery, 724 Fifth Ave., up through Sept. 25). If you’ve already paid a visit to the Whitney’s idiosyncratic large-scale retrospective of the work of the visionary modern American watercolorist whose studies of small-town life have won the admiration of everyone from Edward Hopper to Jerry Saltz, then check out this small, tightly focused museum-quality show. It’s more than a mere pendant (TT).