| Author |
Message |
    
Rudz
Tinkerer
Username: Rudz
Post Number: 1
Registered: 06-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, June 26, 2010 - 05:42 am: | 
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Hi there,
my Pentax Z-1P film camera has a problem:
when setting the lens to "A", automatic aperture, I should be able to select the aperture on the body. When I select 22 on the body for example it does not close all the way.
Selecting 22 on the lens is correctly detected by the body, and the aperture closes all the way.
I assume, it's a communication problem (from body to lens), but cannot find it so far. Does anyone have a repair manual for the Z-1P or a description of all the contact etc. of the KAF2 mount?
Any help highly appreciated!
Rudolf |
Donnie_strickland
Tinkerer
Username: Donnie_strickland
Post Number: 92
Registered: 09-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, June 26, 2010 - 01:47 pm: |
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It's a little new for this forum, but here is a description of the layout of the electrical contacts for Pentax KA body/lens communication:
http://www.bdimitrov.de/kmp/technology/K-mount/Ka.html
And here is the page specific to the KAF2 mount:
http://www.bdimitrov.de/kmp/technology/K-mount/Kaf2.html
Possibly one of the contacts has gotten dirty. |
John_shriver
Tinkerer
Username: John_shriver
Post Number: 59
Registered: 12-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, June 26, 2010 - 06:58 pm: |
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On the Pentax-A mount, control of the actual aperture when the lens is in the A setting is done by the camera, based on how far it moves the stop-down lever on the back of the lens. This remains the same on -F, -FA, and -DA lenses.
The lens has independent adjustments for the diameter of the diaphragm based on the f-stop set on the lens, and based on how far the stop-down lever is moved.
Every Pentax-A lens maintenance manual has a table with "stroke", "aperture", and "stop position". I don't understand the table fully, and I suspect it requires special jigs at least for the stop-down lever.
Also, try another Pentax-A lens. If that one stops down properly, this one has a lens calibration issue. If it doesn't, then the camera isn't moving it's own lever all the way. |
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