I can, I used to work for a photo finisher
In the 70’s Agfa produced ‘roller processors’ it heralded the introduction of fast mass produced film processing.
In order to facilitate this, when films arrived from shops, in large bags the first job was to stick a numbered label on the envelope it arrived in so the finished prints and negatives could be matched up and sent back to the shop.
Second job was to crack open the film can (35mm) and splice all the film received together so they appeared like a cine reel say 50 meters ,each film had a number on it that corresponded to the envelope, so they could be matched up at the end his was done in the dark
Each reel consisted of individual film type in preference of speed( asa ) and manufacturer, once the films had been spliced together, they were then fed in to a roller processor which looked like along box full of metal rolling pins for want of a better description.
The rollers pulled the film in to the machine and through different baths of chemical before running through a cleaning tank, finally warm air was blown on to the film to dry it.
The reels of film were then fed in to a printing machine here filtered (colour balance) light was projected through the negative on to photographic paper which itself was on a long roll.
At the end of the process the film would be cut in to strips matched with the number on the envelope, the prints would then be cut from the roll in to individual pieces placed in the envelope, all the finished work would be put in to the a bag which had the sending shops name on it and sent for despatch.
Transparency film was process in much the same way ,the main difference being that at the end of the process the film was sent for mounting or if the customers preference was un-mounted it would be put in a long sleeve an gently rolled up.
Dunk and Dip
In the 80’s ‘Dunk and Dip’ Systems were introduced mainly because roller processing tended to scratch the film emulsion.
In this system each film was individually removed from the canister, labelled as described above but instead of splicing the films together in to a reel ,each film had a metal clip with a hook placed on one end and a weighted clip placed on the other. The film was then hung on a rack with so the weighted end pulled the film straight.
When fully loaded the rack would move downwards and ‘Dunk ‘ the film in to the chemical baths , up and down they would go from one process to another before going through a blow dryer . the processed film would then be take off the rack and sent for printing .
One of the advantages of ‘ dunk and dip’ was the speed film could be process , a lot faster that the roller method and no scratches.
