I've met both, have books from both, but wouldn't consider them to be similar in style at all. As mentioned above, when I see a Kenna photo, I know it's his, or someone emulating his style. Birds, trees, long exposures...square prints, slight sepia toning are all hallmarks of his style. Dr. Rudman shoots of a variety of subjects, in different locations, uses different developing and toning techniques, is known for his lith work...I guess some of the subjects are similar, but I guess for me I'm too aware of their bodies of work to mistake one for the other. Now if you confused Rolfe Horn and Kenna, that would be understandable (considering the former trained with the latter) as Horn is basically a Kenna clone (even his website is extremely similar to Kenna's).