6 ms·

I'd love if you were able provide some reading on "superblack", or even just explain it yourself. I tried looking it up myself, because it sounds interesting,

by hug 7y ago

I'd love if you were able provide some reading on "superblack", or even just explain it yourself. I tried looking it up myself, because it sounds interesting, but of course search results are polluted with articles on vantablack. "Super black TV" and related search terms just bring up garbage about OLED TVs and such.

p1necone 7y ago
My assumption would be that it's whatever the darkest shade of black representable is - so 0x000000 in rgb. However that can't really be read as a distinct value in an analogue signal, maybe it's some kind of "sufficiently out of range" value so as to be distinguished from legitimate colors?
- kaetemi 7y ago
  I remember there was some particular shade of off-black in Windows 95 that was always transparently showing any video that was playing. Don't think it's related though.
  - zamalek 7y ago
    That happened because 3D cards used something called "overlay". Recall that your 3D card (Voodoo or some other 3dfx) was an additional card beyond your 2D card. The card would overlay its signal on the 2D card according to 2 parameters: a rectangle and a color. I assume that videos used the same machinery, possibly in software, so that you couldn't take screenshots for copyright reasons. Or maybe it was faster for some reason, who knows (Raymond Chen might). Either way, it's probably unrelated.
    - cycloptic 7y ago
      The video acceleration was done the same way with overlays because of the same hardware limitations. I remember the difference was that they used chroma keying to try and fake that it knew how to work with the windowing system -- the hardware would mask the video using the chroma key color while rendering the plane. Of course if you had another window that happened to have the chroma key color for text or something, you could drag it over the video and the text would appear oddly transparent. This happened with certain drivers on Windows up to XP, and on Unix/X11 when using the old "XVideo" extension. But this is indeed tangential and not relevant to the original comment, because the chroma key color could be anything. On one particular driver I had, I remember the chroma key color was a very ugly shade of brown :)
wizzard 7y ago
I believe OLED technology is what OP is referring to. The pixels can turn off individually in order to create true blacks.
- function_seven 7y ago
  OP mentioned 3 magic colors in pre-digital TV production. The 3rd, "superblack" is what we're all curious about. OLED hadn't been invented yet.
Cerium 7y ago
I found a short snippet: https://www.alanpedia.com/television_production_glossary/superblack.html https://www.alanpedia.com/television_production_glossary/sup... Superblack: A value on the wave form monitor of 0 or less luminance units. 7.5 units is standard TV black. Graphics and logos placed on superblack are much easier to work with.
- hug 7y ago
  That's a pretty good dictionary definition, I suppose, but I have no idea what that might actually look like in practice, which is a shame.
  - floatingatoll 7y ago
    On an HDTV with "local contrast dimming", freeze frame at some point in a video where there's only a logo showing in the corner of the screen and the rest of the frame is black. (A screenshot of certain video game loading screens works, too.) You will see that the area around the logo is glowing slightly, and that the area opposite the logo is completely lights out. That is, essentially, the difference between "black" and "superblack". Both areas are displaying black, but one area is backlit and the other is not. Lit black is clearly different from Unlit black, because LCD pixels aren't perfectly opaque. If you have an OLED TV (or an OLED phone, like a top-end iPhones), then every black pixel is superblack, which is why it looks so high contrast and gorgeous. If you have an LCD phone, you can see the "lit black" thing — but probably only if you set it next to an OLED phone. Folks who know what "235" has to do with this, yes, I know, but I'm only addressing "what that might actually look like", not "deep dive into the RGB low/high problem". Feel free :)
derefr 7y ago
Analogue TV encoders took a signal with a dynamic range of "black to white" (e.g. 0V to 5V) and, before modulating it onto a carrier frequency, first compressed the signal upwards, making it into a smaller range of e.g. 1V to 5V, making it into a signal that's actually more like "dark grey to white." Analogue TV decoders did the opposite, treating 1V as the "black level", stretching the 4V "dynamic range" back into the full black-to-white intensity range. Doing this allowed "true 0V" (i.e. gaps cut out of the modulated signal by electronic post-processing, below the "minimum" intensity of 1V, where you're just getting carrier) to act as a form of in-band signalling. 0V was used "outside" the image to both synchronize the TV's raster electronics, and inform said electronics of the period of time they should be off altogether, rather than firing even a weak electron beam. (This most noticably prevents your CRT from drawing a subtle diagonal swoosh when it starts each new frame.) See also: the terms "front porch" and "back porch" (in e.g. https://electronics.stackexchange.com/questions/201011/what-is-front-porch-and-back-porch-of-a-video-signal-in-crt-display https://electronics.stackexchange.com/questions/201011/what-...), referring to the parts of each scanline that are 0V.
- hyperdimension 7y ago
  Interesting to see 'superblack'. I always remember reading the terms 'blacker than black' and 'whiter than white' in old TV repair/theory books.
- taneq 7y ago
  So given that many TVs displayed a flat blue screen on no signal, does that mean that blue is blacker than black?
  - SECProto 7y ago
    I can't recall ever seeing an analogue TV display a flat blue screen - with no signal, they generally display black&white noise
    - gwbas1c 7y ago
      The newer ones made in the late 1990s did.
reaperducer 7y ago
I'd love if you were able provide some reading on "superblack", or even just explain it yourself. I'm not a TV engineer, I was a journalist, so here's what I remember: Superblack was a special kind of black. When you watched analog TV and the video faded to black, the screen was black. But that was a transmission black. It wasn't as black as was electrically possible. There was always still some signal there generating not-quite-black. The not-quite-black was largely an artifact of video tape, and all the dozens of machines a video signal had to go through from playback to broadcast. If you were watching black recorded on tape, it was never quite black. An ordinary person would never notice that it wasn't perfectly black, but you could see it if you were in a TV station with oscilloscopes monitoring the signal at various points in the video chain. IIRC, it was like -1db, or something like that. You could see it at home, if you tried. If you knew what to look for. The easiest way to do it was to turn the brightness up on your TV and look for the dark dark dark grey at the beginning and the end of commercial breaks. That wasn't superblack, that was regular black. But superblack would be next. In a videotape room or an editing suite, you could see superblack quite easily. Watching a tape with black on it on an analog monitor showed regular black. When you ejected the tape, the monitor would go a shade darker: superblack. The blackest the monitor could electrically be without actually being off. Superblack could be used for all kinds of things. I only remember three off the top of my head. First, primitive chroma-key effects in the days before digital video. It wasn't great, and you'd need extra equipment down the line to boost the signal because it would get dark, and then boosting the signal made it look bad, so it was rarely used. Second, the equivalent of today's alpha channel compositing. This was more common, but still resulted in some signal degradation. But it was how you could put chyron or an OTS over video or a live signal. Third, was the TV station equivalent of a "silence sense." When I worked in radio, each station had a gadget called a "silence sense" that would be hooked up to an ordinary radio tuned to the station. If there was silence for longer than x number of seconds, it tripped a relay that flipped on red blinking light bulbs in the DJ booth, in the newsroom, in the PD's office, in the MD's office, and if you were unlucky, the GM's office. In non-studio locations it was often accompanied by a beeping noise. The idea was to let everybody in the building know that something had gone horribly wrong and there was nothing on the air. Some stations I worked at it was set for 10 seconds. Some as few as 3. Really, it depended on the type of music the station played. A similar gadget could be made (most of these things were home-made by the station engineer) to look for superblack in a TV signal. Too much superblack, and alarms go off everywhere. Fourth, Panasonic is the only company I know of that used superblack in the consumer arena. It made a VCR that, after a show was recorded, would automatically rewind and re-watch the show for you. When it sensed superblack, it would mark the location on the tape. Then when a person went to watch what was recorded later, the VCR could sense the marks it made previously and use them to fast forward through the commercials in the program. This worked because there would always be superblack inadvertently broadcast at the start and at the end of each commercial set where there was a break in the video chain from the switch between the show playback machine and the commercial break's playback machines. I had one of these machines. It worked really well, except that it made all kinds of chugging and whirring noises in the night while it marked the tape. Again, I'm not an engineer, so I'm just working from memory. But I'm typing what I know here because so much information about these sorts of things has disappeared, and the people who know more about these things are mostly dead.

by hug 7y ago

p1necone 7y ago

My assumption would be that it's whatever the darkest shade of black representable is - so 0x000000 in rgb. However that can't really be read as a distinct value in an analogue signal, maybe it's some kind of "sufficiently out of range" value so as to be distinguished from legitimate colors?

kaetemi 7y ago
I remember there was some particular shade of off-black in Windows 95 that was always transparently showing any video that was playing. Don't think it's related though.
- zamalek 7y ago
  That happened because 3D cards used something called "overlay". Recall that your 3D card (Voodoo or some other 3dfx) was an additional card beyond your 2D card. The card would overlay its signal on the 2D card according to 2 parameters: a rectangle and a color. I assume that videos used the same machinery, possibly in software, so that you couldn't take screenshots for copyright reasons. Or maybe it was faster for some reason, who knows (Raymond Chen might). Either way, it's probably unrelated.
  - cycloptic 7y ago
    The video acceleration was done the same way with overlays because of the same hardware limitations. I remember the difference was that they used chroma keying to try and fake that it knew how to work with the windowing system -- the hardware would mask the video using the chroma key color while rendering the plane. Of course if you had another window that happened to have the chroma key color for text or something, you could drag it over the video and the text would appear oddly transparent. This happened with certain drivers on Windows up to XP, and on Unix/X11 when using the old "XVideo" extension. But this is indeed tangential and not relevant to the original comment, because the chroma key color could be anything. On one particular driver I had, I remember the chroma key color was a very ugly shade of brown :)

wizzard 7y ago

I believe OLED technology is what OP is referring to. The pixels can turn off individually in order to create true blacks.

function_seven 7y ago
OP mentioned 3 magic colors in pre-digital TV production. The 3rd, "superblack" is what we're all curious about. OLED hadn't been invented yet.

Cerium 7y ago

I found a short snippet: https://www.alanpedia.com/television_production_glossary/superblack.html https://www.alanpedia.com/television_production_glossary/sup... Superblack: A value on the wave form monitor of 0 or less luminance units. 7.5 units is standard TV black. Graphics and logos placed on superblack are much easier to work with.

hug 7y ago
That's a pretty good dictionary definition, I suppose, but I have no idea what that might actually look like in practice, which is a shame.
- floatingatoll 7y ago
  On an HDTV with "local contrast dimming", freeze frame at some point in a video where there's only a logo showing in the corner of the screen and the rest of the frame is black. (A screenshot of certain video game loading screens works, too.) You will see that the area around the logo is glowing slightly, and that the area opposite the logo is completely lights out. That is, essentially, the difference between "black" and "superblack". Both areas are displaying black, but one area is backlit and the other is not. Lit black is clearly different from Unlit black, because LCD pixels aren't perfectly opaque. If you have an OLED TV (or an OLED phone, like a top-end iPhones), then every black pixel is superblack, which is why it looks so high contrast and gorgeous. If you have an LCD phone, you can see the "lit black" thing — but probably only if you set it next to an OLED phone. Folks who know what "235" has to do with this, yes, I know, but I'm only addressing "what that might actually look like", not "deep dive into the RGB low/high problem". Feel free :)

derefr 7y ago

Analogue TV encoders took a signal with a dynamic range of "black to white" (e.g. 0V to 5V) and, before modulating it onto a carrier frequency, first compressed the signal upwards, making it into a smaller range of e.g. 1V to 5V, making it into a signal that's actually more like "dark grey to white." Analogue TV decoders did the opposite, treating 1V as the "black level", stretching the 4V "dynamic range" back into the full black-to-white intensity range. Doing this allowed "true 0V" (i.e. gaps cut out of the modulated signal by electronic post-processing, below the "minimum" intensity of 1V, where you're just getting carrier) to act as a form of in-band signalling. 0V was used "outside" the image to both synchronize the TV's raster electronics, and inform said electronics of the period of time they should be off altogether, rather than firing even a weak electron beam. (This most noticably prevents your CRT from drawing a subtle diagonal swoosh when it starts each new frame.) See also: the terms "front porch" and "back porch" (in e.g. https://electronics.stackexchange.com/questions/201011/what-is-front-porch-and-back-porch-of-a-video-signal-in-crt-display https://electronics.stackexchange.com/questions/201011/what-...), referring to the parts of each scanline that are 0V.

hyperdimension 7y ago
Interesting to see 'superblack'. I always remember reading the terms 'blacker than black' and 'whiter than white' in old TV repair/theory books.
taneq 7y ago
So given that many TVs displayed a flat blue screen on no signal, does that mean that blue is blacker than black?
- SECProto 7y ago
  I can't recall ever seeing an analogue TV display a flat blue screen - with no signal, they generally display black&white noise
  - gwbas1c 7y ago
    The newer ones made in the late 1990s did.

reaperducer 7y ago

I'd love if you were able provide some reading on "superblack", or even just explain it yourself. I'm not a TV engineer, I was a journalist, so here's what I remember: Superblack was a special kind of black. When you watched analog TV and the video faded to black, the screen was black. But that was a transmission black. It wasn't as black as was electrically possible. There was always still some signal there generating not-quite-black. The not-quite-black was largely an artifact of video tape, and all the dozens of machines a video signal had to go through from playback to broadcast. If you were watching black recorded on tape, it was never quite black. An ordinary person would never notice that it wasn't perfectly black, but you could see it if you were in a TV station with oscilloscopes monitoring the signal at various points in the video chain. IIRC, it was like -1db, or something like that. You could see it at home, if you tried. If you knew what to look for. The easiest way to do it was to turn the brightness up on your TV and look for the dark dark dark grey at the beginning and the end of commercial breaks. That wasn't superblack, that was regular black. But superblack would be next. In a videotape room or an editing suite, you could see superblack quite easily. Watching a tape with black on it on an analog monitor showed regular black. When you ejected the tape, the monitor would go a shade darker: superblack. The blackest the monitor could electrically be without actually being off. Superblack could be used for all kinds of things. I only remember three off the top of my head. First, primitive chroma-key effects in the days before digital video. It wasn't great, and you'd need extra equipment down the line to boost the signal because it would get dark, and then boosting the signal made it look bad, so it was rarely used. Second, the equivalent of today's alpha channel compositing. This was more common, but still resulted in some signal degradation. But it was how you could put chyron or an OTS over video or a live signal. Third, was the TV station equivalent of a "silence sense." When I worked in radio, each station had a gadget called a "silence sense" that would be hooked up to an ordinary radio tuned to the station. If there was silence for longer than x number of seconds, it tripped a relay that flipped on red blinking light bulbs in the DJ booth, in the newsroom, in the PD's office, in the MD's office, and if you were unlucky, the GM's office. In non-studio locations it was often accompanied by a beeping noise. The idea was to let everybody in the building know that something had gone horribly wrong and there was nothing on the air. Some stations I worked at it was set for 10 seconds. Some as few as 3. Really, it depended on the type of music the station played. A similar gadget could be made (most of these things were home-made by the station engineer) to look for superblack in a TV signal. Too much superblack, and alarms go off everywhere. Fourth, Panasonic is the only company I know of that used superblack in the consumer arena. It made a VCR that, after a show was recorded, would automatically rewind and re-watch the show for you. When it sensed superblack, it would mark the location on the tape. Then when a person went to watch what was recorded later, the VCR could sense the marks it made previously and use them to fast forward through the commercials in the program. This worked because there would always be superblack inadvertently broadcast at the start and at the end of each commercial set where there was a break in the video chain from the switch between the show playback machine and the commercial break's playback machines. I had one of these machines. It worked really well, except that it made all kinds of chugging and whirring noises in the night while it marked the tape. Again, I'm not an engineer, so I'm just working from memory. But I'm typing what I know here because so much information about these sorts of things has disappeared, and the people who know more about these things are mostly dead.