Would the theory confirm my observation that a long lens has more DOF than a tel e lens of same power at same working aperture? My observation was with lenses of different focals so I'm not quite sure (450 long versus 600T). In other words, does the DOF depend of the lens design or of the angle of the lens? (In my compa rison shots, the crop in the 450 shot corresponding to the 600 frame has MUCH mo re DOF than in the image from the 600T at same f-stop. Has someone tested lenses of same power for DOF?