I know this doesn't help the OP exactly but...
I recently picked up a Mamiya RB and a polaroid back and while shooting I noticed my photos were underexposed using my Gossen Luna Pro. After checking it with my (evil) dSLR I found it to be almostly exactly 2 stops off. I have the 1.5v batteries in the back so I expected it to be off a bit but 2 stops was quite a bit. After a bit of googling I found this site http://www.graphic-fusion.com/lunapro.htm . I do not know the owners of the website but I have reset the calibration of my light meter to read perfectly (when compared to my dSLR) from -1.75EV to 16EV.
The tutorial is pretty easy to read but time consuming and you really need a bright light(s) or large window to get to the higher EV's.
Hope this helps and maybe saves you some money.
Last edited by mr. mohaupt; 05-17-2011 at 06:30 PM. Click to view previous post history.
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