Dark clouds and dim light all weekend, and then, for about a half hour, the clouds opened up in one quarter of the sky, just enough to let in one blazing shaft of light. For a photographer in love with landscape, moments like these redeem whole days of dreary searching for drama, of settling for closeups of moldering leaves. The challenge then, at times when the land ignites like this, is to pay attention to the task at hand — the making of images — instead of simply going down on your knees with gratitude and praise.