Thank you very much David, for your comments, and for your promise to guide members of the forum. An answer like this is what I had hoped for
You are, of course right, that the whole weapon shall be shown as well, although, according to the length of the blade it may be rather small.
One thing, which may help when photographing is, an old umbrella sprayed white at the inside. When strong light is pointed into the umbrella, it is, due to the rounded surface, spread in a nice way, and often avoids shadows.