How Was Video Invented?


[Click] [High-pitched CRT TV noise] Film is a very straightforward technology. It just involves taking a two-dimensional image, and focusing it on to a two-dimensional piece of film, and there you have a photo. But video, and by that, I mean moving electronic images, has a very different history with a lot of changes that have really transformed the way it works. This video was sponsored by B&H Photo, which is kind of fitting because that’s where I get a lot of my gear to make these videos. So I’ll tell you more about them later,
but now it’s off to San Francisco. I’m going to meet with a guy who knows a lot about old video gear and he’s got some he’s gonna show me. – Richard, nice to meet you. – Nice to meet you Derek. Come on in. Welcome to LabGuy’s World. – [Laughs.] That’s a cool spot you got here. – Thank you. – The fundamental problem of video is taking this two-dimensional light image and turning it into a one-dimensional electrical signal. So how do you do that? Well, the solution actually comes from
the first ever fax machine, which believe it or not,
was invented in 1843 by Alexander Bain. Now he was a clock maker. His invention involved a transmitter and
receiver which each had a pendulum, and those pendulums were synchronized. So what would happen is,
at the transmitter, there would be a metal sheet on which something was written or drawn
using a non-conducting ink. – So a finger at the transmitter, an electric finger, would stroke over the paper and wherever there was iron, it would conduct, and that conducting signal was sent to the other end, which was applied to paper with a chemical
that would turn dark when electricity flowed through it, and it would reproduce a very accurate image
of the handwritten note you just made. – Now Alexander Bain
only ever transmitted static images, but some people have called him
the real father of television, because he invented scanning. This idea of moving back and forth across an image, breaking it down into lines. But if you really want to get moving images, well, you need to be able to scan much faster. So we have to jump forward to 1884, and a 23-year-old German University student named Paul Nipkow. He patented what is called the Nipkow disk, which is basically a big disc with a spiral of holes in it. – The inner pinholes do the scanning, and if I go fast enough you can see the scanning. – You would put a light behind this Nipkow disk and so you’d have a spot of light
which scans across your subject, say a person. And then there would be a reflected light off that person
which would be picked up by some light sensors. That would create an electrical signal which
you could transmit over distance to a receiver. Now at the receiver you use that electrical signal
to modulate the brightness of a light source, and then in front of that you place
a synchronized Nipkow disk, and so the result is a recreation
of the image from the transmitter. – So it was just barely at the limits
of the ability to make a viewable picture, and it was actually broadcast
for a couple of years in Britain, and in America and other countries did
experimental broadcasts using this technique. – This is arguably the first-ever
broadcast television image. It was broadcast for a few hours a day for several years, and it was used by engineers to perform experiments
and try to improve the quality of the broadcast. – What it proved was that this wasn’t the way to do it.
[Laughs.] – So by 1939 mechanical TV was all but phased out, and it was replaced by all-electric TV. ♫ Specifically the cathode-ray tube. So this is a glass vacuum tube
with an electron gun at the back. And the electron gun would fire
a beam of electrons at the screen, where it was coated in a chemical which produced light when it got hit by the electrons that’s called a phosphor. And using magnetic fields, this beam
was scanned across the screen top-to-bottom, left-to-right, and you would vary the brightness of the beam by varying the voltage on a control electrode, essentially determining how many electrons would get sent out in that beam at any instant to hit the screen. So, if you send out a lot of electrons you get a bright spot, if you don’t then you get a dark spot, and in that way you can produce a nice black-and-white image. And if you’re wondering about color TV, well, there were a number of dead ends along the path to the red-green-blue pixel system
that became the standard. Like this TV with a spinning color wheel. – I named the project Goldmark I
in honor of Dr. Goldmark. The television part is a standard
black-and-white picture tube. – It displayed 24 frames per second but each frame required six scans: blue-green-red, blue-green-red. It worked really well, but it wasn’t backwards compatible with black-and-white TVs. And this is a mini triniscope, so named for its three cathode ray tubes, one for each color. And their images were combined with prisms. – The downside of a triniscope monitor is that for every inch you add diagonally to your screen the volume of the cabinet increases by like the power of something like three and a half. They get huge fast. – So the ultimate solution was to have red, green, and blue phosphors for each pixel, and three electron guns to determine their relative brightness. – Now, the number of lines those electron beams make across the screen is, in theory, 525 every thirtieth of a second. But this is achieved by scanning every other line each sixtieth of a second, so it actually takes two scans to make one frame. This is called interlacing. And what you’ll notice watching this is that most of the time you’re actually staring at a blank screen. The illusion of a continuous moving image is made possible by our persistence of vision, that is, we don’t stop seeing something instantaneously after light stops entering our eyes. – So, initially I was thinking
this wouldn’t be too hard to film I mean, a thirtieth of a second
or a sixtieth of a second, that’s not terribly fast. But then if you think about it, 262 and 1/2 lines being drawn every sixtieth of a second, that is 15,750 lines drawn per second. That is fast, so if you want to be able to see the lines being drawn on, you need to shoot faster than 15,000 frames per second, a lot faster, really, to be able to see this clearly. and so I am using the Phantom v2512. That is the beast that is allowing me to produce these images. Now the actual resolution of these TVs turned out to be around 480 lines, so when you select 480p on YouTube,
that’s why this is an option. And I guess it’s worth pointing out that the “tube” in “YouTube” is this thing, a cathode-ray tube. So in the time before light-sensitive chips like we all use in our cameras today, how did you actually create the image to display on a television? Well, there were many vacuum tube designs. One of the most common was the image orthicon tube, sometimes called Emmy for short. In fact, that’s where the name Emmys comes from. So the way it would work is you use the camera lens to focus an image onto the front of the image orthicon tube, and that was coated with a photoelectric substance, so it would release electrons in proportion to the light that hit them. Now those electrons were collimated by magnetic fields and sent straight back. So essentially you had an electron version of the image sent straight back to a target, which was a very, very thin glass plate. And of course where there’s more electrons,
that creates a more negative spot on this target. From the back of the tube you’d send forward an electron beam to scan across the target. And so these electrons as they came in, the more negative a spot that was on the target, the more that beam would get reflected. And so that reflected beam was amplified in the tube, and then used as the signal to essentially determine how bright that part of the image should be. So this is how television images were created and displayed for decades. But here is the crazy thing: there was no way to record them. I mean the purpose of video
or the purpose of electronic images was really to transmit something
from one place to another. “Television” literally means “seeing at a distance.” It’s not about recording for replaying later as film was. – The thing that blew me away was realizing that video cameras existed for a couple decades before video tape. – That’s right. That was the the era of live broadcasting – But this introduced some problems. For example in North America, in the US, a lot of the TV programs were produced out in New York, and there was a coaxial cable which went across the whole of the US, and that could deliver programming to, say, Los Angeles. But it was at the wrong time. I mean a news broadcast from New York at 6:00 or 7:00 p.m. couldn’t just be broadcast live at 3:00 or 4:00 p.m. on the West Coast. It just didn’t make any sense, So you needed to time-delay it. So how did they do it? Well the answer was to take a film camera, a cinema camera, and point it at a television screen, and actually film the television screen. Then you would quickly develop the film and bring it back three hours later to broadcast it live, to scan it in and broadcast
that film as though it were live. – But now when I bring it back to the TV studio and stick it into the telecine, [Laughs.] the picture doesn’t look right. The lines aren’t lining up right, and besides you’re trying to sample
two sets of lines back together and they don’t! – This became such a prevalent method of doing business for the TV networks that by 1954 the television networks,
to time-delay their programming, were using more film than all the film studios in Hollywood combined. This is absurd and expensive and wasteful, so a different method was really needed. And that came along in 1956 with the invention of the first workable video tape recorder. It was the size of a large desk and it cost a fortune. It ran on this two-inch magnetic tape with little video heads spinning at 14,000 RPM. We’re talking as fast as a jet engine. That is the kind of technology it took before
video became what we kind of know it as today, a method of recording and storing images, rather than a way of just transmitting vision from one place to another. But we’ve come a long way since then, miniaturizing the tape stand into VHS and Beta, and eventually down to DV and mini DV,
and now we are on to solid state storage. And you know I’ve glossed over a lot of the history here, but now we’re in a situation
where video is better than film. You can see that in 2012,
that was the inflection point between people using film to shoot the top-grossing movies,
changing over to people using digital. And what this has done for people like you and me, is it’s made it possible to make really good images.
[Music] And the question I have is,
what does this do to a society? What might it do when people can share
every part of their lives with video? ♫ This part of this video was sponsored by B&H Photo, literally one of my favorite stores in the world. They have all the greatest and newest camera gear, plus pro audio and lighting and computers, basically anything you could need to make high-quality video. And every time I’m out in New York,
I go and visit the store. The last time I was there I asked them for a gimbal, because I’ve been seeing all these comments saying my videos were too shaky, and so they recommend that this one right here, and I’ve really loved it. It’s so smooth.
I can hold it with one hand. It is pretty lightweight and it’s just been great
and I think it’s really improved the quality of my videos. And when I’m back here in LA,
I still shop with them online, because there is no shop like that in LA. In fact, this camera, the Sony a7R III,
I’d highly recommend it, I bought it for my wife for Christmas
the Christmas before last, and it was backordered, but you can actually sign up through their website to get notified when it’s in stock, and I did that and managed to get it
in time for Christmas, so it’s a really great shopping experience. The people are so knowledgeable, it’s a mom-and-pop shop, it’s got anything you could ever want. I highly recommend that you check out B&H Photo.
I’ll put a link to them in the description. And thanks to B&H for sponsoring this video. ♫

Leave a Reply

Your email address will not be published. Required fields are marked *