Hi Beryl, I like your begonia but, I am sorry to say, the picture is way to soft. The DOF is very good and I do not know how you know it was at f5.6 but I take you word for it, in this case the photo was cropped very close, although I do not see much deterioration there. One of the things that may have deteriorated the sharpness is the blurred object on the right edge of your picture. This would have effected the sharpness of the whole image. Did you use a tripod? If you, once in a while, want to use your 400mm lens for close-ups use a extension tube. It is cheap and may give you a lot of pleasure. However, to me a tripod is a must. Attached is an example with a 150-500mm lens at 500mm with a extension tube.