I must admit that when the Greg Myers was writing these blogs, I really wasn’t paying too close attention to the content of his posts. I read one or two, and seemed to be good solid information. Now that he is gone, I intend to further the information highway by putting up little tidbits about photography, when they come to mind.
Today I would like to introduce you to the Brick Wall Test. What is the brick wall test? It is the easiest and most accurate test of lens sharpness, both center and edge. First, be sure that your camera is on a solid tripod. Use a bubble level, or hot shoe mounted bubble level, to confirm level operation. With prime lenses (non zooms) simply shoot in the manual mode, or aperture priority, wide open at 10 feet, then again at other apertures. Naturally, if you are using a very long lens, with a minimum focus distance in exess of 10 feet, work with the minimun footage available. With zoom lenses, do the same thing, but also at different focal lengths of the lens. Before purchasing an additional lens, you may want to ask your dealer to do the brick wall test. Already own all the lenses you need? Do the test anyway to learn the characteristics of your lenses. It is much smarter to shoot a job at the sharpest parts of your lenses. Also, don’t be fooled into thinking that all of one kind of lens has the same characteristics. Seldom is that true. You may even find a soft spot in one of your lenses that lends itself better for portraits. Test everything!