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- เผยแพร่เมื่อ 6 ส.ค. 2024
- There are a lot of short videos on analog video, but you'd have to watch a lot of them to get the full picture, and there's a fair bit of misinformation out there. This video is for my students in media technical theory class, but I hope that others will enjoy it. Here's a fundamental explanation of how NTSC analog video works. Even in today's digital video universe, it's good to know the elements of analog video, as we're still living in an analog world, and because digital video equipment still starts off as analog.
![[ไฮไลต์] แบดมินตันชาย วิว กุลวุฒิ (ไทย) vs LEE Zii Jia (มาเลเซีย) รอบรองชนะเลิศ | โอลิมปิก 2024](http://i.ytimg.com/vi/mvBiEAqlssw/mqdefault.jpg)
My dad told me all this when I was younger. He was very into the electronics of it when the first person on his road got one of the very first tv.’s. He became an electrical engineer and taught me as I was growing up. I even helped him as a keen child and teenager. Thanks dad. Miss you xx
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*So why the heck are ya making it public, remember do what you can Donald Trump will have to go to prison.😎*
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You explain more clearly than any teacher I've ever had.
I still have trouble wrapping my head around the part about color encoding
I am continoually amazed at just how complex analogue black and white tv is, i keep reading articles over and over but still cant seem to recall all of it, its magical
Thank the men who designed the circuits. Especially color TV which required very complex equations for the circuitry.
also the math that describes the linear systems and filters!
I am an electronic technician for so many years. Fixed crt tv many times but I've never known how the crt actually works until I saw this video. Thank you so much.
i personally am fascinated on how analog and UHF/VHF television works.
Become a ham! Amateur radio operators are permitted to transmit analog television signals in the UHF bands. Unfortunately, there isn't sufficient bandwidth in our VHF allocations for TV, but we can send analog still images--called Slow-Scan TeleVision or "SSTV" on nearly all bands, including the shortwave bands.
Dana Lee unfortunately passed away over 6 years ago. He was a professor in the Radio Television Arts faculty at Toronto Metropolitan University (Ryerson Uni at the time) for many years.
I was fortunate enough to have him as my professor for first year technical class for my university degree in 2016. He passed away a year later from brain cancer, but he was telling stories and getting visits from students right up until the end.
May these videos carry his passion and spirit for the craft and history of television for a long time to come.
this is one of the best explained videos i've ever seen :D
I did not understand the part of the sync signals? Care to explain
@@frankservant5754 you play your jazz drums with your jazz solo, doing things that are really really hard to follow in time, so in a constant basis, you hit the cowbell so the rest of the musicians don't get lost and the music flows with syncronisation and everything is clear
is the same in the tv, the signal is your drum solo, the tv is the rest of the musicians and the cowbell is the sync signal
When I was 14 years old in 1969, on my way home from high school I would pass by a shop in Hunter Street, Newcastle, called "Radio Rentals". For some weeks they had this TV set on display, either in the front showcase window, or inside the shop itself. It was a "Baird"(brand) colour TV, switched on and showing a colour bar generated by a TV pattern generator. This set sticks in my memory for one real reason, and that's the way the stations were selected. It had a vertical column of knobs labelled BBC1, BBC2, then ITV1 through to ITV9. Below the station selector knobs were the customary picture and sound controls, Volume and Tone for the audio, Brightness and Contrast for the video, plus, being a colour set, it had the Colour control which would adjust the saturation of colour, then a Tint control which controlled the hue. Not being able to see inside the set I couldn't tell if it was valve or transistor circuitry, so, being 1969, I can only assume it was valve circuitry. But being British-made, it was a PAL-system set. I learned many years later that the Tint control, even in valve-circuitry PAL sets was superfluous. It was just an added extra to give the user an extra knob to twiddle, nothing more.
I keep forgetting how much later Britain got color TV.
@@DanaTheInsane We in Australia only got it in 1975!
I have a side gig digitizing home videos and was looking for a way to explain analog video (and why it's never going to look quite the same was digitized) to a client and this was the first one that came up, which gave me a chuckle. I had Dana as a prof while at Ryerson RTA and it's nice to hear his voice again. Not sure why so many of the good ones leave us before their time but I'm glad he left us a bunch of his knowledge.
this is awesome! I mean you would rarely find videos on study material soo good that it covers half of my portion in one video... amazing explanation.. thanks. :)
The NTSC (National Television System Committee) is the first compatible color broadcast which is backward compatible to the existing black and white TV receivers. And the color NTSC receivers is also backward compatible with the existing monochrome signal. Therefore it deserves respect. The Never Twice Same Color often happens during the vacuum tube era which as the tube heats up more, you need to re-adjust the tint control. But during the 1970s when transistor TV receivers was developed although out TV still has a tint control but we hardly touch it.
bobskie321
I must agree with you. What NTSC did was to prove that a compatible colour TV was possible and to get it working. It's an amazing achievement and the fact it remained in use for so long is testament to the sound principles of its basic design. Where PAL and SECAM won out is that their designers were able to see NTSC working, and learn lessons from it. But that would not have been possible if NTSC hadn't been there first.
Well the developers of PAL certainly learned their lessons, and as a result developed a SUPERIOR colour TV system. The SECAM developers learned stuff-all as they developed a system that couldn't even be used in a studio without massive image problems. In fact, I read it in a reputable electronics magazine that French TV stations had to be kitted out with PAL-system cameras, VTR(videotape recorders), Telecine players, video mixing desks and other gear with the signal only transcoded to SECAM at the transmitter end. This is because SECAM gear could not handle switching from one camera to the next without the colour going totally "skewiff"(bad colour mismatches) but Gallic pride and obstinance forbade the French from admitting they "stuffed up"!
bobskie321
the french have unique designs, they are always very original,
No good being "original" if all you produce is SHIT!
It´s amazing what they did and the concepts related with analog broadcast TV. Outstanding video! Thank You!
Ill never forget our first color TV set. It was a Zenith large rectangular picture tube. I think the year was 1963. I was 7 years old. I was fascinated. That TV set set me on my journey into electronics. I am now a retired electronics engineer. It still amazes me how the people who designed B&W and then color TV, were able to do that with only tubes, resistors, caps and picture tube.
Damn, that was awesome. I'm an analog audio guy and honestly had very little clue how video works (until now!). This all makes total sense and that was a FANTASTIC explanation! Thank you!
I find analog distortion very satisfying
HooperScooper it be banana
Same
Because analog is natural.
On flashing difference entire screen at a time instead of pixel at a timd and angling shadding of difference time banwidth then motion display happened. So 3 timers drive three lamps then sine or cosine timer is all data needed is time phase angle. Thanks. This is best engineering textbook presentation i had seen. Supper..you deserve great reveer and respect and reward from youtube...🎉
This is a very comprehensive and informative video! Detailed information is well presented, thank you for your effort.
i paused and wound back several times and now I am an analog video frickin' genius. :D great vid!
Would you mind sharing resources dude. I mean I understand what he's saying but I need to know exactly how. 🥲 Iykwim
What an amazing video. I learnt everything about analogue tv now
awesome video..very detailed yet short explanation of everything...
Excellent tutorial! It's always good to explain how it all works in an analog way, cause as much as its all digital now, it always starts out analog, and eventually gets converted back to analog. I ve been in tv broadcasting for 30+ years and went thru this big change to digital broadcasting... interesting how we still use analog in some way. Folks still need to know analog. Nice vid!
Awesome! Thank you very much!
This is an amazing video. I have to check out your other stuff. Thank you
Nice! Great video. Also, Hovhannes (Ivan) Abgari Adamian (Armenian: Հովհաննես Աբգարի Ադամյան; 5 February 1879 - 12 September 1932) was an Armenian engineer, an author of more than 20 inventions. The first experimental color television was shown in London in 1928 based on Adamian's tricolor principle, and he is recognized as one of the founders of color television.
This was way more information than I wanted, thanks
fucking mind blowing. my class was crazy confusing but you just made my all nighter into a mere 2 hour trek! thank you crazy much!!!!
Amazing video and extremely well explained!
Excellent video! Thank you (9 years later it's still great)
Resolution of analog pictures are finer than digital because they have no pixels. The shadow glide (transition from light area to dark area) of analog pictures is smoother than digital because in the latter the shadow glide goes in numerical steps from light to dark, resulting in "mapping" or "flaking" of skins of the subject. This bothers me but it's OK for others.
Us digital retards dont pay attention to the pixels. Thats how we arent bothered by them.
Brilliant, very nice animation and good explanation
Good info. Thanks for the video.
Best video on the subject. Thank you very much
This is awesome!
Thank you so much sir for your packaged information.
This type of tv was the inspiration for my art movement, clothes photograghing!
Very helpful- thanks!
This so fascinating
Even as a kid I loved playing with my aunts tv the tuning the picture going fuzzy I loved seeing a picture come through or going fuzzy
And how things worked analoge is great
Simon Willis analog is the Best.
If you like fuzzy picture composite cabels are the way to go!
A good addendum to this documentary would be an explanation of how basic picture controls work.
During the last 60seconds, "Phase" is discussed: the temporal alignment of the color subcarrier. The phase control long ago became known to consumers as the Hue, or, Tint control. Its purpose was to maintain the proper time alignment between the Luma(original black & white) and Chroma(color subcarrier) components of a NTSC broadcast picture.
Thus, "Tint" really has only ONE correct setting - the setting that aligns that color burst synch to 180deg. A calibration test pattern, plus a blue filter or blue-only mode, can be used to arrive at that setting. And the value of that setting may vary from set to set.
For Tint, and as for the other user picture controls(Brightness, Contrast, Sharpness, and Color)' there are no "preferred" settings, just CORRECT settings, which will allow one's analog or digital TV set to effectively become an extension of the studio broadcast or cinematic chain, guaranteeing viewers the most accurate image their display can deliver.
Zickcermacity You're quite right! I decided to leave it at the point I did, so that viewers who were interested in exploring further could do so on their own. I do appreciate your thoughtful comments - thanks!
The problem is that today, despite leaps & bounds in quality and reliability of flat panel TVs, and the superior consistency and quality of digital TV(HD and SD), most of these panels are set up in a most non-standard mode at the factory, to compete with one another in retailers and dealers.
Things weren't any better during the old analog(CRT Tube) era, but I'm a believer in educating consumers what the controls do, and what features can be disabled, and actually improve picture quality and transparency.
I highly encourage viewers here to look up Joe Kane and the work he has done to attempt to bring accuracy to the viewing experience for the average consumer and for the upscale home theater owner. Calibration in a sense "removes the TV" from between source and viewer, allowing them to see exactly what the producers and directors of shows and movies want that material to look like.
Neat video! Thank you!
At first didn't want to watch the video because I thought it would be too basic, but it went into about as much depth as I wanted.
Thanks for the video!
one of the best videos.
I bought a video capturing device that turns analog RCA audio and video to digital via USB...
I captured video and I see a horizontal desynchronisation between the horizontal lines...which makes edges look like zig zag...mostly when the movement of people or objects is greater...how can I get rid of that? Can I use a software to correct that after I captured the video? Or is there a software that corrects that while capturing the video?
thanks!
Omgosh this just helped me so much
You are no human ! ! amazing video
Very Informative
Excellent video. I have been trying to fix the pcb board that drives a crt. The hot keeps burning out and there is no high voltage. I suspect the horizontal frequency is wrong.
The fact that people figured this out... along with other amazing things like telephones, cars, rocket ships to the Moon, et cetera....
Thank god for nerds, dorks, dweebs, and geeks!
Using degrees on a circle to encode colour is very clever because it gives you a wide range of values to play with.
Unfortunately this also makes the signal highly susceptible to colour drifting - you risk having your entire colours shifted if there's even the slightest phase delay.
THANK YOU for this. 👏💕
this videos is great, lots of thanks
I've heard that if you appear on a tv program with a green screen you need to be careful of what color clothing you wear or the cameras won't even be able to see you. How does that work?
That’s if you wear green in front of a green screen
Thats is called Chroma Key. This is used to display any kind of video graphics behind objects or people. Classic example is an Weather Forecast, where someone is in front explaining the weather conditions, while the city/country/world map is being shown behind. In reality it is just a person in front of a green screen. How this work is simple - on video processing, you select one color - in many cases green - and inject a different video feed whenever a green color would be displayed.
great video! :)
Those guys back in the 'old days' were a lot smarter than everybody gives them credit for today.
Wow very amazing
hello, does the CRT Camera has a shutter? If yes, how it works?If not, how to control the exposure? Aperture and ND filter?
As i understand the tvs oscillator recreates the color burst signal from the refrence point. So i guess that signal is unmodulated which it will then compare to the modulated signal.
Good explaining
Thanks this was very useful. I’m looking at restoring a few vintage 405 line televisions here in the U.K. I think this very old standard has some differences to what you described but it was still very useful. I’m looking at the waveform from a 1960 pattern generator at the moment and hope you will take a look and share your advice. Great video thanks for sharing.
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SECAM is the best! Probably because it's french(or maybe because the color component uses FM modulation which is the more robust)
For the French, the biggest selling point of SECAM was that it's not American ;-) Something Essentially Contrary to the American Method.
Mandolinic It's exactly that. NTSC uses quadrature amplitude modulation causing 2 problems:
1)color shift if there is phase shift in the receiver
2) The frequency between the luminance carrrier and the color subcarrier has to be an odd multiple of the line frequency to avoid ugly patterns of intermodulation between the two carriers from appearing on the screen, which leads to a crappy framerate of 59.xxx fps (interlaced). SECAM uses FM for color subcarrier so it is more robuust inna RF rransmission and it uses a delay line so it does not have to transmit the red and blue chrominance information at the same time on the same carrier, which allows better colors. The 2 problems of SECAM are incompatibility and it's a little bit more expensive.
is very informative video about video signal in crt
Is Analog TV and how it works similar to how computers show video? If not, what is the difference since CRT computer monitors look similar to old TV sets?
I can see how crt cameras emulate the mechanical tv cameras. They use magnetic fields to bend the light as apposed to the physical changes using discs to modulate the intensity of the light on the photo-sensitive element. And then the image viewer follows the same path as the camera to make the image appear, just like the spinning discs. With both systems, synchronization is imperative to see an image. With the mechanical system, the speed of the disc would most likely need to be constantly adjusted, whereas the electronic version, the sync signals are built into the carrier wave. Very interesting. I wonder why the vertical hold knob was easily accessed in the crt tvs while the horizontal control was seldom seen.
With extreme high resolution digital then it is as smooth as analog but can be more slective in precision like stepper motor or anticolision technology or airplane position air and ground speed calibration
Thanks for this video
ভাল লাগলো!
Muito boa explicação
nice explanation
modulation is one of the coolest things in this world
Ahh, Analog TV. I miss it. I still wholeheartidly believe that governments should have no power in whether or not channels broadcast in analog or digital, that should be the stations individual choice.
I subscribed because of this Video ❤
Thanks a lot
You would be a great narrator for horror stories! Maybe hit up
*"Chilling Tales For Dark Nights"*.
@1:19 why magnetic polarity not constant?
European PAL system works in the same way. The difference is that the modulation of the color signal is inverted every line. This is to compensate color deviations.
thank you
have you tried to pick up old analog signal with an old tv? there are signals up there that you can pick up. i dont know how to do this if you try and your able to pick them up, let me know... the signal is bouncing the the clouds... gov said they were going to use the old analog air space for emergency communication? there using it but not for that, there are video images and audio, maybe you can figure it out.... let me know if you do figure this out.. I have more infor if you decide to try to find the video and audio up there....larry
A colour picture is basically three pictures in one.
Can you do PAL (Phase alternating line) video?
All principles presented here are same for PAL and NTSC. Differences are quite small and you need to know details about QAM (quadratic AM modulation) to understand it. In short PAL modifies every second line of chroma signal to correct phase error that can occur during transmission. So PAL receivers don't need hue control.
There are also differences in timing - every european system (also BW) is 25fps, american 30fps. European PAL use 50Hz for vertical scanning, 15625Hz for horizontal scanning and 4,43MHz for PAL color subcarrier.
JacobTHESitton
Following on from the excellent answer by xsc1000: In practice the NTSC system suffered from an issue where phase shifts in the transmission chain caused colour errors on the screen. The PAL system developers designed this problem out of their system by inverting the phase of the colour signal on every other line, with the colour burst at the start of the line telling the monitor what was the reference phase for that line. This is a relatively minor change, but it meant that a colour error on one line was compensated by a colour error in the opposite direction on the following line! When integrated by the viewer's eye, the errors cancelled out and the overall colour was more stable. As TVs were developed over time, they included a one line delay which meant that errors could be compensated by electronics within the set, rather than by eye.
One minor detail that gets overlooked is that with NTSC, bright parts of the image are transmitted with a high amplitude signal, and dark parts with a low amplitude signal. This is reversed in PAL. This meant that when an unsuppressed motor bike went past your house, instead of creating white spots on the screen, it created less visually intrusive black spots.
My most recent TH-cam Video I posted was in Old Fashioned Black and White.
Thanks
Nice
My third eye is open
The CCDs quickly replaced the iconoscopes in the 1970s. Iconoscopes were huge devices and to use 3 of them just to have color on TVs was not very feasible... That's why when CCDs appeared color TV became more viable. Sure it was possible to make color TV with 3 iconoscopes but then the cameras would become humongous, seriously they were already quite large and expensive with just 1 iconoscope... So yeah CCD chips made color TVs economically viable pretty much.. And specially when it became possible to have all 3 colors on a single CCD chip. Nowadays we have CCDs and CMOS chips.
? they have been using tubes for quite a long time ccd came into vogue somewhere around the mid 80's. I guess somewhere around '83 for studio work and late 80's for ENG field work. Which was not really possible before anyway. They used 16mm film for field 'news' work before that. I still prefer 3ccd rendition for color (colour lol) over bayer but that's just my personal pet peeve.
The size of tube studio camera's was not really an issue (I guess) the tubes are pretty small too, What was an issue is thermal expansion so the thing has to be re-alligned once in a while and afterglow effects which are very visible on 70's recordings when there are disco lights involved. I guess sensitivity is an issue too although this is all guesswork on my part I was never a camera operator it's just what I remember from TV. And I guess the ENG thing is more of a matter of the betacam recorder then the tube versus ccd thing but what do I know. It's possible a field three tube camera uses a lot more power so that's an issue. Although at some point I did have a philips consumer camera from the mid 80's that had a single tube that did colour. It used a filter screen with vertical stripes like yellow/white/cyan so the electronics could get colour out of it. It didn't suck that much power but recorder was not included. I fiddled around endlessly with the little pots inside to get a nice picture and eventually gave up it was not that bad though a bit insensitive. Insensitive in terms of when you point it outdoors at night only the lamps would show up..
I case anyone is wondering the camera used the different amplitudes coming from the tube to syncronize the colour circuitry. so the white/transparent bits gave the highest amplitude and so the electronics 'knows' how to lock-in and decode the colour.
Umm, RCA, Phillips, Bosch and others made color TV cameras using 1” or 11/4” tubes, tube sizes dropped to 2/3” and even 1/2”tubes before CCD’s took over. Tubes had several flaws, they had to get aligned and replaced. A new set of three tubes was around $10,000 in the mid 1980’s.
Play Nintendo on CRT only.
How is the scanned beam converted to a signal?
I believe the light charges the photographic plate to a certain level. It's a bit like seperated islands like a ccd. Anyway, there's a secondary plate that collects electrons (from the beam) that are scattered of the photograpic plate or rejected which has a relation to the charge that that 'pixel' had before the beam hit. It's something like that.
@@alexstevensen4292 I wish I understood this
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It would have been more consistent to stay with camera tubes for color. Introducing CCDs when describing the basics of color TV was unnecessary and confusing.
Otherwise quite a good video.
Along with CRT displays they were the last bastion of electrons flying around in an evacuated glass enclosure.
When comparable CCDs' became cheap and expensive plumbicon tubes became even more expensive than they already were the choice was inevitable. Nevertheless, I still have lovely examples of old technology.
In 2018: the price of a studio tv camera (head only - no lens) costs some £30-40,000. A nice new 3 - 4 bedroom home now costs around 10 times that give or take.
In 1968: a new EMI2001 British made studio colour tv camera cost around £25,000 at a time when such a sum would buy six 3 bedroom houses. A new Rolls Royce, Silver Shadow was around £3500 (the price of six new Ford Cortinas).
Technology is so cheap now that people tend to take it all for granted. Professional electronic engineers are now less valued in society than hairdressers. It is incredibly sad.
It's weird to me how only one dimension of information (ie. voltage) was required to convey something as complicated as a picture with colour ranging from darkest black to whitest white in addition to light and shadows.
Okay...
The color television works like our eyes
wow!
Don't you a transcription? Thank you.
Awesome video (+1)
So basically everything is a varied voltage signal, which IS proportional to current, because of ohms law. 🐒, Umm.. so it's current x resistance makes voltage. And since they all play together so we'll voltage changes and so does the rest of 3m (current, resistance... Watts..) 🌞
It's all because of changes in environment that also is related to voltage, etc. So technically everything is related in some way (exsistance). So if that's true, then a butterfly flapping its wings and one part of the world has an effect on another part of the world..
Resistors are very cool simple components.
Just learned how to read "voltages" and current, n display/re-represent them. I also learned another cool thing about operational amplifiers today... They can amplify that signal.
😁
It seems we are advancing everyday... We were dumber yesterday than we were today. Why? Where did we come from..? Why didn't we know how to fly to the moon yesterday..?
Everything is basically a reflection of itself.. were all bouncing around and mingling inside this reality we call exsistance, and it seems the entire time of her existence we've been trying to stabilize things.. get a perspective on things if you will..
Analog tv is d best they just keep going n going
Anyone ever tell you that you sound a bit like Michael Keaton?
if there is a magnetic field/energy in the sky and if the clouds are man made cloud , could an image be produce in cloud like and old tv.. i have video of something happening like this in the clouds.. the clouds are man made.. if this is possible i have more infor about the clouds i been filming them for over 3 yrs and figured out alot of info... i will send you more info i seen images made of clouds. i used filter on camera and saw moving images in the clouds like inverted color of what look like watching a tv....
PAL Rulezzz ;D
PAL60 is better
Yes, the German-developed PAL(Phase Alternating Line) colour system was, and is, by FAR the superior colour TV broadcasting system as it also has 100 extra scan lines, 625 lines as opposed to just 525 lines in NTSC.
Yeah, well, the extra scan lines only happened because the frame rate was lower. Which happened because current alternated at a different frequency in Europe. But all systems suffered from the fact that they had to be backwards compatible to the B/W signal.
The lower(50 Hz) frame rate meant that the video was scanned through at the standard rate of 25fps(frames per second) but backward-compatibility is not the downfall that you make it out to be. It was necessary so that older monochrome sets could still be used. Basically the chroma subcarrier(be it PAL, NTSC or that abominable pile of shit, SECAM) was "piggy-backed" onto the video signal for colour sets to detect and decode while monochrome sets simply ignored it.
Nice but complicated.
That's life
At least try to understand
Color*