1. An apparatus for imaging a surface of each of a plurality of embossed metal containers, one at a time, as each said container passes by said apparatus on a metal container production line, said apparatus comprising: a light source; a collimating lens positioned to be illuminated on a first side by said light source and to output substantially parallel rays of light from a second side in response to said illumination; a beam-splitter mirror positioned to first reflect said parallel rays of light; a focusing lens positioned to receive and focus said first reflected parallel rays of light forward to a focal point and toward a substantially concave surface of a metal container, having an embossed portion, such that a first portion of said focused rays of light may impinge substantially perpendicularly on said substantially concave surface of said metal container and subsequently reflect off of said concave surface back to said focal point and backward through said focusing lens toward said beam-splitting mirror, and such that a second portion of said focused rays of light may impinge substantially on said embossed portion and subsequently reflect substantially away from said focal point and said focusing lens; a camera lens positioned to receive said subsequently reflected rays of light after said rays of light pass backward through said focusing lens and through said beam-splitting mirror; and a camera having an optical aperture and positioned to capture said rays of light received by said camera lens and adapted to generate an image of said concave surface of said metal container in response to said captured rays of light such that at least an outline of said embossed portion is substantially discernible within said generated image.