Apparatus for detecting commercial variations in at least a portion of an at least partially transparent container having an open mouth, that includes: at least one light source (14, 16, 88, 414, 515, 615, 715) to direct light toward a region of interest of the container such that the light reflects off the region of interest as reflected light rays extending at different reflection angles; a plurality of light sensors to receive the reflected light rays, wherein parallel reflected light rays travel to common portions of the light sensors including individual light sensors of a plurality of light sensors or individual cells of an individual light sensor of the plurality of light sensors, and non-parallel light rays travel to different portions of the light sensors, wherein the light sensors are used to establish a light pattern in an angular domain such that a point in the light pattern is generated from a signal from a corresponding portion of the light sensors and represents a light intensity corresponding to a particular reflection angle, wherein the location of this point is determined by the angle of the parallel rays; and a processor to receive signals from the light sensors and differentiate between different types of commercial variations in the container by analyzing the light pattern in the angular domain, characterized by a plurality of angular domain lenses (Lens 1) between the light sensors and the region of interest, a plurality of masks between the region of interest and the light sensors to block other light rays from impinging on the light sensors wherein the masks include masks in spatial domain image planes produced by the plurality of angular domain lenses, and a plurality of relay lenses (Lens 2) between the light sensors and the masks, wherein the domain and relay lenses cooperate to redirect the reflected light rays so that the parallel rays travel to common light sensors of the light sensors and so that the non-parallel reflected light rays travel to the different portions of the light sensors. at least one light source (14, 16, 88, 414, 515, 615, 715) to direct light toward a region of interest of the container such that the light reflects off the region of interest as reflected light rays extending at different reflection angles; a plurality of light sensors to receive the reflected light rays, wherein parallel reflected light rays travel to common portions of the light sensors including individual light sensors of a plurality of light sensors or individual cells of an individual light sensor of the plurality of light sensors, and non-parallel light rays travel to different portions of the light sensors, wherein the light sensors are used to establish a light pattern in an angular domain such that a point in the light pattern is generated from a signal from a corresponding portion of the light sensors and represents a light intensity corresponding to a particular reflection angle, wherein the location of this point is determined by the angle of the parallel rays; and a processor to receive signals from the light sensors and differentiate between different types of commercial variations in the container by analyzing the light pattern in the angular domain, characterized by a plurality of angular domain lenses (Lens 1) between the light sensors and the region of interest, a plurality of masks between the region of interest and the light sensors to block other light rays from impinging on the light sensors wherein the masks include masks in spatial domain image planes produced by the plurality of angular domain lenses, and a plurality of relay lenses (Lens 2) between the light sensors and the masks, wherein the domain and relay lenses cooperate to redirect the reflected light rays so that the parallel rays travel to common light sensors of the light sensors and so that the non-parallel reflected light rays travel to the different portions of the light sensors.