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Tammons
Tinkerer
Username: Tammons
Post Number: 1
Registered: 04-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, April 04, 2010 - 01:28 pm: | 
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Its way out of whack.
I found the 2 potentiometers, and I assume its a pretty simple procedure, IE 18% gray card, adjust A to this, B to that etc.
Any help would be appreciated.
Thanks |
Mareklew
Tinkerer
Username: Mareklew
Post Number: 33
Registered: 03-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, April 04, 2010 - 03:08 pm: |
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For most light meters, that are CdS based, one pot will adjust offset (roughly) and the other - sensitivity. As a rule of thumb the resistor in series with the cell will have to be adjusted to roughly the cell resistance in the middle of measurement range. But effectively you will need some reference light source and reference meter, to adjust/verify at several points throughout the range. Since CdS meters are inherently non-linear you will have to figure out a setting that will result in a minimal error at all light levels (it will be always possible to fit two points, but it may lead to an excessive error somewhere else on the curve).
Marek |
Tammons
Tinkerer
Username: Tammons
Post Number: 2
Registered: 04-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, April 04, 2010 - 06:04 pm: |
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Yashica FX 2 meter adjustment.
I got it.
This was done with a new zinc air battery
I don't know if this is the correct procedure, maybe I got lucky.
The far left pot seems to be sensitivity.
Not really sure but it did the best almost at its lowest setting. Counter clockwise is lower. Clockwise is higher. Very close to the lowest setting IE counter clockwise almost as far as it would go worked best with my camera.
That was the pot I set first.
The pot towards the front of the camera seems to affect the meter directly. Counter clockwise is meter +, clockwise is Meter -.
Right now that pot is about 1/3rd up from the bottom.
I set it up with 2 other metered cameras I know are right, with the same lens length both on matrix meter.
A Nikon 35Ti and a Nikon SLR film body.
Set it up generally to shoot at iso 80. Checked it at ISO 32 and its right on.
At iso 400 and 800 its close.
At iso 1600 its probably off by about 1/2 stop.
Checked it out indoors and outdoors and it seems pretty close all the way around.
Maybe this blurb will help someone else with a FX that's out of whack.
Its not that hard, but it was a lot easier when I pulled the entire top off and reinstalled the speed/iso dial on the naked top.
BTW you have to ground the prong on top of the prism to get it to turn on.
I taped the gold on/off leaf/switch so it would stay on while testing.
Below is where my pots ended up.
You can see the gold switch. Its the long gold blade just under the rewind post.
The contact is the post below it.
Thanks for the help.
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