ANN ZAHN'S 30-year retrospective at Strathmore Hall Arts Center surveys the impressive career of a Washington printmaker for whom art and life have been inseparable, the outpouring of work unstoppable. An ode to the joys of working at home, her color and black-and-white etchings, lithographs and relief prints constitute a visual diary of things that gave her pleasure on any given day -- a lotus blossom in her garden, the Lazy Susan on the kitchen table, her family, the endearing Assateague ponies she etched after rowing from her vacation house to observe them. Best of all are the Edenic meditations on a small goldfish pond in her yard, which have the limpid quality of watercolor and occasionally recall Matisse and Chagall. A fine little illustrated catalogue accompanies the show. Happily, many of these prints are still for sale.