Tom,

This is really good stuff and very technical in nature. This is something that I am very much aware of when photographing knives close-up when the knife is at an angle. When shot on automatic exposure, many times I find that the camera selected an f stop somewhat larger and it tends to render the photo somewhat blurry at the near end and far end. I mostly take these types photos with a tripod and select aperatuture priority. The higher f stop selection generally results in slower shutter speeds but results in sharper images.
To illustrate the point here are two photos of a piece of crown antler that were taken on a tripod at the very same distance and focal length. The first photo was taken on automatic exposure and resulted in an exposure of 1/100th sec @f5.
The second photo is aperature priority setting. I selected f16 the camera set the exposure @ 1/5 sec. The results are night and day. Notice how the foreground is blurry in the first photo. If left up to the camera this is what you get. The second photo is sharp from front to back. No other photoshop corrections were done except for cropping. This is one way to get better photos just by using the f stop correctly and I thank Tom for posting the idea.

Best,
Warren