Summer Group Exhibition. This show at the Rule Gallery has an informal quality, nonetheless it's excellent. The first thing up is Mary Ehrin's installation made of tubular metal, faux crystals on chains and white feathers. The Ehrin crowds the things near it, so make a point not to miss the marvelous suite of Andy Libertone drawings that are partly hidden by the installation. Next to the Libertones is a selection of Jeff Starr's outlandish ceramics, including several bongs. Across from the Starrs are gorgeous photos by Jason Patz who, since 2002, has been taking his own picture. Despite the constrictions implicit in self-portraiture, he's been able to create a wide range of visual experiences. On the opposite wall are two intriguing paintings by one of the acknowledged contemporary masters of the area, Dale Chisman. Around the corner is a single sublime painting in a deep aqua with multi-colored lines done by Clark Richert, another local master. This show bring together several generations of Denver artists from old-timers who started their careers in the '60s to kids who weren't even born until the 1980s. Through September 10 at the Rule Gallery, 111 Broadway, 303-777-9473. Reviewed August 4.