View Full Version : Help: Shepherd FM990 Flash/Light Meter

30th March 2010, 09:09 AM
I have one of these units which seriouly needs re-calibration. I believe it could be two stops out in the general reading. (The light value it suggests is 2EV higher than it should be.)
The main circuit board inside shows 4 variable resistors in a square formation. Can the reading be adjusted through altering these resistors? If so which way? I am not sure how to tweak these to give a truer reading.
Does any forum member have knowledge of these units? Please advise.

John WB