Nikon AM 120 macro lens

[felix5616]

what bellows dram would one need using a nikon 120mm AM macro lens with 4x5 film to get 2:1 macro?

[Tom Monego]

I believe 480mm would be 2:1, used to know this stuff.

Tom

[Dan Fromm]

The magic formula is: rear node to film distance = focal length * (magnification + 1).

The lens rear node is approximately at the diaphragm, so is a few mm in front of the board. Extension will be approximately 120 * (2 + 1) = 360 mm.

[Walter Calahan]

Damn if I own the lens but have never used it at 2:1 to know this detail. I do know to always measure from the nodal point, but all those formula learned in class decades ago have faded away. Grin. Good luck.

[felix5616]

Thanks