Some "N" scalers (model railroad enthusiasts) had their cute little trains on display at my local library. These trains are 1/160 actual size, and the track rails are only 9 mm apart. They look bigger in this cha-cha as my stereo base was only about 2 cm (less than an inch). Depth of field was shallow as in all macro shots, but I cheated a little by focusing the first shot on the front of the engine, and the other on the middle of the car behind it. When fused in 3D it gives the illusion of more DOF than there actually is.
