The way I think of it is the faster the shutter speed, the less light. Therefore the diaphragm is open more to compensate, using lower f-stops. The lower the f-stop, the less depth of field.
ok now I need to understand if the depth of field shrinks proportionally with the shutter speed? The faster the shutter speed, the less depth of field? I should ask Al, I suppose.
The depth of field effect is really pronounced in this one.