Pentax 645 Auto Bellows Set
For magnifications of 1.0x-3.2x with the 55mm f/2.8 lens, 0.8x-2.3x with the 75mm f/2.8 lens, and 0.44x-2.7x with the macro 120mm lens, the auto bellows 645 unit extends between 54mm and 180mm. By mounting the 55mm f/2.8 lens in reverse, the maximum magnification can be improved to 4.3x.