Quote Originally Posted by cao
Now you're standing exactly where I am with this. The Sp F does default to a centered position, whereas the previous Spoties do not. Since the net consists entirely of resistors whether variable or not with the exception of the meter coil, it seems that recalibrating for silver simply means changing the hairspring arm so that the meter is centered which 3.4uA flows (15% increase) through the winding.

For diagram see page 23 (pdf page 24) in: http://www.pentax-manuals.com/markro...t_cam_spii.pdf
Warning: 11mb file
Yes, tweaking the hairspring arm would seem to be the way to do it, although, as I say, I would doubt whether 15% would be a significant difference. Apart from the mechanical innaccuracies of the camera when new, there are also the effects of 30/40 years age to consider! If the shutter speeds have all become a bit slower over the years and a slightly high meter needle means you tend to stop down a little more, the two might counter one another to give the right result! Another option that wouldn't even need the top taking off the camera might be to fudge the ASA setting. Probably the only acid test is that of suction and observation, ie suck it and see!
Best wishes,