Matching serial numbers on 12 back

[flashbulbman]

Just got an old style 12 film back from Ebay. The seller did not mention the serial numbers on the ad. When I looked at it, the numbers do not match. Is that a big deal like some say it is or should this be a non issue? The insert goes in smoothly. I will test it in a few days (or should I send it back)?

 

[Victorh]

Identical numbers for housing and insert are often used as a positive argument to buy when in fact there is no real advantage.

Condition of the back and service history are more important features.



Vic.

 

[michaelhcothran]

Now I thought, and had read in years past, that the matching numbers indicated that the insert and shell were hand calibrated to each other at the factory, insuring proper film alignment. I would suspect that tolerances, even with non-matching backs, would still be acceptable, but perhaps not as close as with matching numbers.

 

[Victorh]

Michael,


The only part that controls correct film plane is the film frame of the housing.
The insert does not have any influence on this alignment.
It may come as a surprise to you that the insert is not even there when the film frame is adjusted!





Vic.