My Minolta XM recently got an AE-S automatic viewfinder - completely by chance.
The viewfinder was offered to me when I bought a Canon T90.
Since this viewfinder is very rare, of course I couldn't say no. In addition, the piece was in mint condition
The AE-S has a silicon measuring cell, in contrast to the AE automatic viewfinder, which uses a CdS cell that reacts more slowly to changes in brightness.
The viewfinders, which can be changed, communicate with the camera via electronic contacts:
Two fresh 1.5 volt button cells failed to work after having triggered the camera a few times.
The XM's mirror remained up, which, according to the instruction manual, indicates low battery voltage.
Previously, the red LEDs next to the shutter speed scale in the viewfinder also failed at irregular intervals.
I suspected the corroded battery holder. There are probably contact problems.
I assumed the metal screw shutter could electrically not close properly with the camera ground that forms the metal chassis.
Not unusual for Minolta cameras of this area (1970ies).
First I went over the base plate with electronics cleaner on cotton swabs. There was some dirt coming off.
A continuity check with the multimeter showed that there was no current flow in some areas:
So the Dremel Stylo had to intervene.
First with the hard rubber tip...
… and then with the stainless steel brush:
Now the base plate was shiny and the current flow should be restored without restrictions.
The continuity measurement no longer showed any blocking resistances.
A voltage measurement of the positive pole of the battery against ground (screw cap) confirmed the success of the measure.
Open circuit voltage 3.17 volts.
This should be enough to get the XM running error-free again.
To be on the safe side, I cleaned all the contacts on the viewfinders and in the camera's viewfinder housing with electronics cleaner.
The cotton swabs were gray afterwards. So we did the right thing.
The obligatory exciting test ...
... everything now as it should be.
The camera triggers, the mirror falls and the viewfinder displays in the AE-S automatic viewfinder show plausible behavior
Even for smaller, spontaneous projects, the table quickly becomes too small
Here is a comparison of the two automatic viewfinders:
Left AE-S, right AE
The blue silicon cell in the AE-S ...
... and the CdS measuring cell in the AE, each located inside above the eyepiece:
I don't know which combination I like better.
With AE-S and focusing screen G (matte fresnel field only):
Or with AE:
Maybe I need a second XM?
___
Information about the XM/XK/X-1 on The Rokkor Files
+++
All information provided without guarantee and use at your own risk.
The viewfinder was offered to me when I bought a Canon T90.
Since this viewfinder is very rare, of course I couldn't say no. In addition, the piece was in mint condition
The AE-S has a silicon measuring cell, in contrast to the AE automatic viewfinder, which uses a CdS cell that reacts more slowly to changes in brightness.
The viewfinders, which can be changed, communicate with the camera via electronic contacts:
Two fresh 1.5 volt button cells failed to work after having triggered the camera a few times.
The XM's mirror remained up, which, according to the instruction manual, indicates low battery voltage.
Previously, the red LEDs next to the shutter speed scale in the viewfinder also failed at irregular intervals.
I suspected the corroded battery holder. There are probably contact problems.
I assumed the metal screw shutter could electrically not close properly with the camera ground that forms the metal chassis.
Not unusual for Minolta cameras of this area (1970ies).
First I went over the base plate with electronics cleaner on cotton swabs. There was some dirt coming off.
A continuity check with the multimeter showed that there was no current flow in some areas:
So the Dremel Stylo had to intervene.
First with the hard rubber tip...
… and then with the stainless steel brush:
Now the base plate was shiny and the current flow should be restored without restrictions.
The continuity measurement no longer showed any blocking resistances.
A voltage measurement of the positive pole of the battery against ground (screw cap) confirmed the success of the measure.
Open circuit voltage 3.17 volts.
This should be enough to get the XM running error-free again.
To be on the safe side, I cleaned all the contacts on the viewfinders and in the camera's viewfinder housing with electronics cleaner.
The cotton swabs were gray afterwards. So we did the right thing.
The obligatory exciting test ...
... everything now as it should be.
The camera triggers, the mirror falls and the viewfinder displays in the AE-S automatic viewfinder show plausible behavior
Even for smaller, spontaneous projects, the table quickly becomes too small
Here is a comparison of the two automatic viewfinders:
Left AE-S, right AE
The blue silicon cell in the AE-S ...
... and the CdS measuring cell in the AE, each located inside above the eyepiece:
I don't know which combination I like better.
With AE-S and focusing screen G (matte fresnel field only):
Or with AE:
Maybe I need a second XM?
___
Information about the XM/XK/X-1 on The Rokkor Files
+++
All information provided without guarantee and use at your own risk.
Last edited:
