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Machineboy
Tinkerer
Username: Machineboy

Post Number: 19
Registered: 01-2008

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Posted on Friday, February 29, 2008 - 12:10 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

Hi guys, just got a nice Sekonic light meter, model L-248 that didn't work. After some fiddling on the inside of the metering mechanism, I realized that the battery test switch was always on, making the meter really "hot" ie. spiking at all times.

After loosening a screw the needle fell back to normal position, and now the meter reacts very nicely to light. The problem is that when I compare it to the light meter in my digital Canon G9, the meter underexposes at about -2 stops. Is there a way to recalibrate the meter?
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Machineboy
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Username: Machineboy

Post Number: 20
Registered: 01-2008

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Posted on Friday, February 29, 2008 - 12:33 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

I think I found the answer myself. There is a small adjustment screw just to the left and down from the light sensor. Turning it clockwise lowers the sensitivity. It only went down about 1 stop, so there isn't that much leverage. Still, I think the meter is more accurate now.
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John_shriver
Tinkerer
Username: John_shriver

Post Number: 24
Registered: 12-2006

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Posted on Saturday, March 29, 2008 - 08:14 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Moderator/Admin Only) Ban Poster IP (Moderator/Admin only)

If you used a modern 625 alkaline cell, that's why the meter is two stops off. It is designed for a mercury battery, which has been banned world-wide.

You could use a Wein zinc-air cell. Alternately, a 675 zinc-air hearing aid battery from the drug store, with an o-ring for spacing and a washer for shimming.

Or, have a Schottky diode added to the circuit to drop the voltage, and use a silver-oxide 625 cell.

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