Come April, photography blossoms in New York City like buds on the trees. For those who like a little competitive action, Christie’s, Phillips de Pury and Sotheby’s all hold their big photography auctions. For a more relaxed experience, it’s off to the annual AIPAD Photography Show, Apr. 10-13, 2008, at the New York Armory on Park Avenue. Sponsored by the Association of International Photography Art Dealers, the show, now in its 28th edition, presents more than 75 dealers from the U.S., Canada, Europe and Japan.