Red window in back of FED1 camera

Hi, I suspect this has already been covered before but I see on the early FED http://www.ebay.com/itm/Fed-1a-SN-2278-extrimely-rare-1934-year-/262592281107?hash=item3d23b83a13:g:~nsAAOSwawpXvdJy on EBay, there appears to be a red window in the back. Is this related to the days when B&W film had a paper backing? My understanding was that there was only a short paper 'leader' and 'trailer' allowing the film to be loaded etc., in daylight. The only 35mm film I know of which had a complete paper back was 828...

Cheers,

Steve

Hi Steve,

As far as I know, this window regularly exists, up to c. s/n 10xxx.
It is normally covered by a screw. It was used to regulate the lens and body. Fed cameras were not standardized...

A hole exists in the press film for the same reason, up to s/n c. 15xxxx, that time.

Amitiés. Jacques.

At this câmera the little round back cap is lost.
Regards LP

Many thanks for explaining,

Steve