Hasselblad SWC scale focusing

When setting the closest distances on the SWC focusing ring, do you measure the distance from the front of the lens to the object or from the film plane to the object?

I think it makes a difference with the lens wide open.

i have one, but its not in front of me at the moment, i believe its 12 inches. the measurement is also from the film plane.

You should measure the distance from the film plane i.e. roughly from the slot where you put in the dark slide. For accurate focusing you can get the RMXD adapter.

Thanks, I've been measuring from the lens and no wonder my pictures are out of focus!

At least the A12 film magazines have a film plane index (a ring with a vertical line through it) on the right side of the magazine housing. It's about 1" or 2.5 cm above the bottom of the magazine. Measure from there and you'll get millimeter precision. (On the left side of the magazine, you can measure from the chrome metal rim (?) about 1/16" (1.5mm) behind the darkslide slot, which should be within tolerances for anything except maybe extreme macro work.)
This goes for all Hasselblad V-series cameras, not only the SWC.

//Björn