Why did drum scanners give way to other technology?

[Lachlan Young]

Remarkable, isn't it? You guys were actually scanning film, at A0 size, at resolutions meaningful for high-quality printing in the late 1970s.
At around the same time or even a few years earlier, my dad was working at a publishing house where he was responsible for transitioning the content-to-press process to the first generation of digital technology. Apparently, the resistance among the more conservative of the printers to this development was massive (and, of course, futile).

2000spi scanning on a machine everyone would immediately recognise as a drum scanner was being done from the end of the 1940s, albeit scanning direct to separations with vacuum tube logic to correct for colour & contrast. Time-Life was the first major adopter/ funder of this technology. At this point in time, a great deal of traditional colour separation contrast/ colour correction for print (especially rotogravure) was done by skilled hand retouching on glass plate separations, not by register masking (that would need the introduction of PET film base a decade later to really become dominant).

It really took Rudolf Hell's innovations at the start of the 1970s (putting an image manipulation system between scanner and film writer) to really begin to compete more effectively with traditional pre-press.

 

[calebarchie]

I have a feeling you are not talking about (photographic) film scanning…

Yep, therein lies the answer though.

@koraks You were describing the basis of a flying spot scanner, just pointing out the related and pretty relevant history of telecine.

@Scott J. Actually, the majority drum scanners moved the pickup head (light source and pmts) instead of the drum. Scanmates did the opposite and had issues, just off the top of my head.

 

[Scott J.]

Actually, the majority drum scanners moved the pickup head (light source and pmts) instead of the drum. Scanmates did the opposite and had issues, just off the top of my head.

You might be right. The Howtek/Aztek scanners definitely utilize a movable drum (i.e., the light source and optics bench remain stationary). I always thought other table-top drum scanners utilized a similar design, but now that I'm looking more closely at some pictures of a Screen DTS-1030AI (just as an example), it does look like the light source and optics bench are connected and move in unison relative to a stationary/non-translating drum.

In any case, what I was more cautioning against in designing our hypothetical PMT flatbed scanner was the situation where you had a light source and an optics bench that were not rigidly connected (for whatever design reason) and had to move on independent carriages. That would be a nightmare for maintaining beam alignment (which is obviously why the drum scanner manufactures avoided it!).