The difference here is that you can achieve a much larger extension without fear of bending the tubes or causing damage to the camera mounts due to the over-hanging weight of the tubes and lens. The commonly used Nikon bellows are the PB-4 and PB-6 units. The Nikon PB-6 Bellows permit fully supported extensions up to 208mm for reproduction ratios to nearly 11:1. Or in excess of 400mm if the PB-6E Bellows Extension is attached, for magnifications up to 22:1. The Nikon PB-4 Bellows also incorporates a tilt and shift mechanism on the front extension column, which can be very handy for “squeezing-out” a few more millimeters of depth of field from the lens!

Mounting of a camera body onto the bellows can be tricky and damaging to the camera mount if done incorrectly. One important step to do is to make sure that the red lens alignment indicator is at the 9 o’clock position (see animation below).