Many older lenses can’t simply be attached to DSLRs like my D7000 because the flange focal distance (lens mount to the focused image) is too short. DSLRs have a mirror, which gets in the way and makes the FFD almost 3 times as long.
My solution is to attach another lens to focus on where the sensor would be for the primary lens. To minimize length, I turned the secondary lens into a macro (close-focusing) lens by mounting it backwards.
My friend Matti and I made a rail system to hold the camera and lens with his laser cutter. Special thanks to Station House Studios for lending me the lens that inspired me to make this adapter.