Tiny holes in Kodachrome II - what were they for?

[andrewmore]

I've been re-mounting some of my late father's 35mm slides from the early/mid-1960s, some of which were shot on Kodachrome II.

On one side only of the Kodachrome II film, every four perforations, is an additional small round hole in between, and lined up with, said perforations.

What purpose did these additional holes serve? I've never seen them before on 35mm film.

Thanks in advance for the answers which I'm sure will come.

Regards

Andrew More

 

[Rangefinderfreak]

Just a guess: As all slides were mounted in cardboard frames, it might be for the cutter machine to line the frame edges so the image would be positioned right.

 

[andrewmore]

Thanks. This would get the vertical alignment sorted out between the perforations I guess, but I would have thought the perforations alone would have sufficed for this. I don't think it would deal with the length along the perforations though as the start/finish of each film will be slightly different depend on how the film was loaded. More to the story I think.

You mention cardboard mounts, but here in the UK (and maybe Europe as well) there was always the option of having the film returned uncut which is what my father did. He then mounted them in Agfa glass-mounts which got very grubby and covered in an almost oily haze so I've been re-mounting them in new plastic glassless mounts.

Regards

Andrew More