7 ms·
Eidophor
- avinash 7y agoI 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.
- taffer 7y agoI wonder what the advantages / disadvantages were compared to CRT projectors that came out in the 1950s.
- mannykannot 7y agoFrom the article: the Eidophor was 80 times brighter than CRT projectors of the time. Presumably because it was a modulator of an independent light source, rather than the source itself.
- amelius 7y agoSince it uses a "slowly rotating disk" for the projection, what was the latency of the technology?
- avian 7y agoThe rotating disk is only there to replenish and renew the oil surface on which the electron beam is drawing the image. The speed of disk rotation has no effect on the latency. It does have an effect on persistence of the image, but my understanding is that the disk was slow enough that movement was negligible compared to how fast the oil deformations faded. Eidophor has practically zero latency, same as a CRT - whatever the electron beam draws is immediately visible.
- sp332 7y agoFrom http://www.earlytelevision.org/yanczer_eidophor.html http://www.earlytelevision.org/yanczer_eidophor.html they could run at 120 Hz.
- baobrien 7y agoMike 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 https://www.youtube.com/watch?v=3-BvMcqEc98
- beautifulfreak 7y agoHe mentions the Eidophor's only competitor, the GE Talaria, which is also interesting: https://en.wikipedia.org/wiki/Talaria_projector https://en.wikipedia.org/wiki/Talaria_projector
- plutonorm 7y agoI wonder if you could do digital holography with this?
- trhway 7y agonot sure about holography, i think one can imagine how an electron beam modulated surface (or may be volume) can say change laser direction thus providing kind of non-mechanical scanning in a lidar for example. Though it sounds like a last century approach. These days i'd bet on something like nanotube channeling the beam and say flexing in response to the field.
- yborg 7y agoFascinating. I always wondered what was used in the 1960s to project the huge screens in NASA Mission Control.
- acqq 7y agoI 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-unknown-widely-used-projector/ 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"
- pmcjones 7y agoDoug Engelbart's famous 1968 demo used an Eidophor.