Originally Posted by P719C1
The FED displays sounded promising (and to a lesser extent the similar SEDs), offering the best of all worlds except for the lack of multisync capability, but if I recall correctly there were legal and manufacturing issues with them, and the display manufacturers had just invested so much in LCD and plasma technology that they were reluctant to immediately produce something that would put both to shame.
I'm surprised at people still bring up the FED myth
that they would have been CRT quality.
FED needed to do PWM -- essentially tantamount to multiple-pulsing / temporal dithering -- so you would still have plasma-like or DLP-like pixel noise, especially in dark colors. In real CRT tubes, the massive gun allowed the beam spot to have a peak 5000cd/m2 illumination, which allows squeezing a lot of light into ultrashort time periods (aka "low persitence") with adequate average brightness levels. In a proper CRT, the electron dot is so bright that when the electron beam stops scanning (i.e. deflection goes AWOL), it actually is too bright to stare at and burns a hole through the shadow mask. True tube CRT scanning overexposes in high speed video, showing how ultrabright the electron beam dot is, in a real CRT tube. But the tiny microguns in FED couldn't do that, so the persistence is longer (much, much more motion blur than CRT) in order to compensate for the lack of energy behind each pixel. The dimmer pulses had to be sustained via multiple-pulsing, lengthening persistence which increases motion blur, and creating temporal-dithering side effects. Talking to retired researchers who used to play with FED confirms this. Because of the PWM and the inability to do concentrated peak brightness at low single-pulse persistence, FEDs are NOT CRT quality motion
. CRTs had fast response and low persistence. Where FED has fast response but high persistence. Which unfortunately creates motion blur (same problem for OLED motion blur
). Fast pixel response doesn't fully eliminate motion blur if you still have high persistence. Now, let's talk a proper low-persistence rolling-scan OLED (e.g. like the one Oculus DK2 uses), but capable of <1ms persistence, and we're talking a proper and worthy CRT heir!FED had temporal noise artifacts (ala plasma/DLP)FED had high persistence despite fast responseFED had much more motion blur than CRTStop spreading the FED myth that it is CRT quality
P.S. Used to own an NEC XG135 CRT projector, DiamondVision CRTs, and many other 21" CRTs