One of the five mega-sized Polaroid cameras made in the late 1970s, now owned by John Reuter’s 20×24 Studio, made a one-day-only appearance in Rockland July 1, in conjunction with local photographer Joyce Tenneson’s exhibit of images made with one at Dowling Walsh Gallery. The cameras, and examples of images made with them — including one of Tenneson’s — was featured in the New York Times last month. The artist took advantage of its presence here to make a number of 20×24-inch Polaroids.