Last week-end was a rather sunny and warm exception to the usual chilly weather we've had recently in Brittany. I set off with my Pentax 6x7,
and found that the meter was giving me strange readings. Compared to "sunny 16" there were 3 to 4 EV differences. I'd been used to about
1 since the camera had been serviced a couple of years ago.

Is this happening often ?
Could this be caused by a weak or inappropriate battery (I currently have 4LR44) ?
Is there a way I can adjust the metered prism finder myself ?