If you want to copy of an old photographic colour slide or negative, say, to post online or to make a copy of someone else’s slide, what do you do? You take a photo scanner if you have one (I have a Canon flatbed scanner with a film and slide copier in the lid), scan in the image (I use 3200 or 4800 dots per inch), and, of you are a perfectionist, tidy up to dust marks and scratches with Photoshop or similar. It makes for a better quality image than you ever used to get projecting the slide on to a glass bead screen.
But what did you do in the pre-computer nineteen-sixties and seventies? Think: Tandy TRS-80 introduced 1977, Sinclair ZX80 and ZX81 in 1980 and 1980, the 8-colour BBC Microcomputer in late with 1981 and the Sinclair SX Spectrum in 1982. None of these would have been capable of running photo-scanning devices even if they had been available. For example, to Hewlett-Packard Scanjet was introduced in 1987. It operated in black and white at 300 dots per inch, could handle only reflected documents and not film or slides, and cost a fortune.
So what did you do? Another trip to the loft has found my slide copier.
It was terrible. I could never get it to produce a decent image no matter what kind of lighting I used.
For example, here, in a copy from a friend’s slide, I am nearing the top of Ben Nevis in April, 1974, straight up from the Glen Nevis car park. It has not been Photoshopped. I did not even manage to get the light consistent on this one. You didn’t get to see it until the film was processed, and the cost meant you couldn’t have as many goes keep trying until it was right.
Looks like another item for metal recycling. Thank goodness for modern photo scanners.
For the sake of completeness, here are the instructions that were in the box (or download as pdf)