Ricklb55
Member
This is how to fix an ME prism finder whose brass pins no longer adequately connect to a film back. You will only need a #00 Phillips screwdriver and I recommend that it be magnetic. Depending on your eyes, you may find you need some kind of hands free magnifying device.
With the ME prism finder separate from the camera body, turn the finder to an upside-down position with the eyepiece towards you. Locate the brass pins. They are located in an assembly that can be removed from the finder by removing the four screws at each corner. Do not remove the two screws in the center of the assembly. BEFORE REMOVING THE ASSEMBLY: be aware that in the assembly there are two very small brass pins (not the connection pins) that are pivot pins for the connection pins and once the assembly is removed these small pins can fall out. They are not loose and will not fall out easily but can. With the finder's eyepiece still towards you, remove the assembly keeping it level. Turn the assembly upside down by revolving it towards/away from you - NOT left/right. You will now see two polished pieces of steel at each corner that are in the shape of the letter L. These pieces of steel are the springs for the connection pins and are the cause of the problem - they have become bent with time and are no longer doing a good job. They are held down by a single screw. Loosen that screw but do not remove. Rotate the steel L 180 degrees. Now you can bend the steel L down until it is flat. Rotate back to the original position and tighten the screw. Rotating the steel L around then back is a bit tricky but not difficult. Repeat on the second steel L. Replace the assembly.
This procedure should also work on the SQ AE prism finder. I have both and it appears both are using the same assembly, but I have not remove the assembly on the AE prism so I cannot be certain.
The fact that the steel L will bend with time implies that your Bronica camera should not be stored with both the finder and film back attached.
With the ME prism finder separate from the camera body, turn the finder to an upside-down position with the eyepiece towards you. Locate the brass pins. They are located in an assembly that can be removed from the finder by removing the four screws at each corner. Do not remove the two screws in the center of the assembly. BEFORE REMOVING THE ASSEMBLY: be aware that in the assembly there are two very small brass pins (not the connection pins) that are pivot pins for the connection pins and once the assembly is removed these small pins can fall out. They are not loose and will not fall out easily but can. With the finder's eyepiece still towards you, remove the assembly keeping it level. Turn the assembly upside down by revolving it towards/away from you - NOT left/right. You will now see two polished pieces of steel at each corner that are in the shape of the letter L. These pieces of steel are the springs for the connection pins and are the cause of the problem - they have become bent with time and are no longer doing a good job. They are held down by a single screw. Loosen that screw but do not remove. Rotate the steel L 180 degrees. Now you can bend the steel L down until it is flat. Rotate back to the original position and tighten the screw. Rotating the steel L around then back is a bit tricky but not difficult. Repeat on the second steel L. Replace the assembly.
This procedure should also work on the SQ AE prism finder. I have both and it appears both are using the same assembly, but I have not remove the assembly on the AE prism so I cannot be certain.
The fact that the steel L will bend with time implies that your Bronica camera should not be stored with both the finder and film back attached.
