from Hacker News

Eidophor

by foo42 on 9/21/19, 9:41 AM with 13 comments

• by baobrien on 9/21/19, 2:38 PM

  Mike Harrison of mikeselectricstuff gave a talk at the 2016 Hackaday Belgrade conference on how insanely complex these things were.

  https://www.youtube.com/watch?v=3-BvMcqEc98

• by avinash on 9/21/19, 11:11 AM

  I am quite impressed by the image quality and the sharpness for something that was used in the 60s. Of course, digital screens are better now but whoever invented the Eidophor at that time did extremely well.

• by acqq on 9/21/19, 9:42 PM

  I remember "live" projections of a TV video signal used in BBC programmes in late seventies, where you see on the stage a huge screen and seemed that it's not a film projection, and at that time I just couldn't imagine how they managed to do that, knowing only how the CRTs worked -- and big projections simply "didn't fit" that model. I considered that a pure magic.

  And now searching the internet, they really did have this technology (see the comments):

  https://hackaday.com/2016/03/15/retrotechtacular-eidophor-an...

  "When I worked at the BBC West London studios in the 70’s we regularly used Eidophors for back projection"

• by yborg on 9/21/19, 5:20 PM

  Fascinating. I always wondered what was used in the 1960s to project the huge screens in NASA Mission Control.

• by amelius on 9/21/19, 2:01 PM

  Since it uses a "slowly rotating disk" for the projection, what was the latency of the technology?

• by plutonorm on 9/21/19, 2:40 PM

  I wonder if you could do digital holography with this?

• by taffer on 9/21/19, 1:10 PM

  I wonder what the advantages / disadvantages were compared to CRT projectors that came out in the 1950s.

• by pmcjones on 9/22/19, 4:49 PM

  Doug Engelbart's famous 1968 demo used an Eidophor.