Quote from: Herman Trivilino on December 26, 2014, 03:59:15 AM
Nice photography, Jan. I agree that we are looking at an image of a lamp shade in that last photograph. Note that it appears round because the reflecting surface is flat. I believe you'd see a similar image produced by a curved bevel, but the image of the round lamp shade would be oval-shaped.
Thank you Herman. You are correct. Nevertheless for growing distance of the lamp from the bevel the eccentricity of the oval-shaped image will increase and in a limit case it will change to a line. A good reminder how the rays reflect on a curved mirror can be found at the following address:
http://en.wikipedia.org/wiki/Curved_mirror Relevant for our discussion is the table "Effect on image of object's position relative to mirror focal point (concave)".
I agree that the scratches on the bevel complicate the reflected image of the lamp substantially because the light is interfering on it. However for me even the blurred images support enough the explanation why a flat bevel and cylindrically grind bevel looks differently in reflected light.