Two Beer Steins with Lithophane Bottoms

probably German, (1) with ornately floral cast-pewter lid attached to white porcelain half-litre stein decorated with a picture titled “Eine Weihnachts-Überraschung” in the bottom of the stein is lithophane of a beer drinking scene. 9 1/4" high. (2) decorated with a scene of a man playing a string instrument for his girlfriend, the base with a lithophane of a nude woman. 6 1/2" high. The lithophane process is considered "pre-photographic" and relies on the varying depths of the porcelain to form the image when held to the light. This idea of using the depth of a material to form an image was used in pigment photographic processes. Ex Spira Collection.