Why Inventing Color TV Was So Difficult [video]
Comments
grishka
pavlov
SECAM was pretty crazy because it required a delay line: a memory that would hold the previous scanline so it can be combined with the current one.
Without digital circuits, the delay line was a piece of glass. You’d convert the video signal to a sound wave, send it through the glass, and (hopefully) get it back exactly 64 us later so it aligns with the next scanline.
Here’s a picture: https://www.eevblog.com/forum/projects/glass-ultrasonic-dela...
grishka
Yes I did read about these while doing my research. Also fascinating. Most (or maybe all?) PAL TVs also have a delay line to correct for phase errors. That ability is what differentiates PAL from NTSC, apart from timing.
lbourdages
Fascinating! So it's a bit like a plate reverb (used in the olden days in audio engineering), but in the MHz range.
AlexDragusin
Alec Watson from Technology Connections did an entire series on this subject:
(How Analog Color TV Works: The Beginnings) https://www.youtube.com/watch?v=dX649lnKAU0
Then the playlist on TV stuff: https://www.youtube.com/watch?v=l4UgZBs7ZGo&list=PLv0jwu7G_D...
Don't blame me for the rabbit hole :P
pavlov
Tintin readers will remember the pains suffered by viewers of early color TV experiments (“The Castafiore Emerald”, 1961).
thunderbong
Thanks for the Tintin reference! I immediately knew what you mentioned as that panel flashed in my mind.
I don't know what it is about the Tintin comics, but for many of the fans, the panels are so strongly memorable even after so many years, is quite amazing.
mpalmer
In the first 90 seconds, the narration refers to "the insane 19th century electronics that made color possible", but is referring to the 1900s, which were the 20th century.
The video contains no insight at all into "why" color TV was so difficult. It just lists and describes a few key advancements.
Also the "invention" of color TV is very different from the commercialization.
chmod775
Very common for this format. It looks and sounds like something of substance on the surface, but ultimately it's just going through the motions and droning on to fill 10 minutes. Like a high-schooler with an assignment to give a presentation on some topic, but with higher production quality.
It does not have to be coherent, because it's entertainment, closer to a sitcom than educuation. If you think about it too hard you'll ruin it for yourself.
Before you blame YouTube and AI though, have a look at what documentaries on TV are and used to be like. With few exceptions they're not much better.
pack_stimulus
I disagree. I think the video clearly described the challenge, somewhere in the middle of the video, as sending TV signals that both BW and color TV sets could decode, and went on to explain how that challenge was solved by "inventing" separate Luma and Chroma signals. Did I miss something?
ck2
Before Youtube and Wikipedia there used to be a great website I liked to read about Philo Farnsworth but cannot remember the name of it for the life of me now
reader9274
farnovision.com ?
I grew quite an appreciation of color TV recently when I made a software-defined SECAM decoder. It's mind-boggling that they were able to do this with 60s technology, to be honest. But then what do I know, analog electronics is witchcraft to me :D
https://github.com/grishka/miscellaneous/blob/master/AVDecod...
edit: I watched the video. It only took them until the 13th minute of a 15-minute video to show something resembling a real video waveform, lol. That's, uh, not how you explain how TV works.