This is my most recent addition to my
vintage video camera collection I've got quite a few things in there I'd like to
show you but this one pushed itself right to
the top of my list. It's a 1984 RCA CKC021,
color videotube camera which doesn't matter,
because we're not going to look at it and we're not gonna look
at it's picture we're gonna look at its viewfinder. [snap, snap] If we take a look in here- -you'll notice right away that it's in color and some people watching this get why that's a big
deal and are freaking out and others have no idea why that's special. That's understandable, color viewfinders are very
common nowadays. Here's a 1993 Sony Handycam
with a color viewfinder. You can tell because it was still such a selling
point they printed it right on the outside. If we take a look in this one you'll see it's got,
uh, quite a nice picture, nice color rendition But- that's because it's based on
mature LCD technology. By 1993 you could make a color LCD and put it
in just about anything and these became very popular. In the 80s, however, color LCDs weren't
really a thing you could have. The first full color consumer LCD
that I'm aware of came out the same year that this thing did,
in a little pocket television. so the technology was brand new
at that point. So what they had instead in camcorders
were cathode ray tubes This one has one.
Let me show it to you. This one was made by Hitachi who, incidentally, probably made that one,
and just rebranded it for RCA. You can see the picture from this one
is also color but if we take a look in the viewfinder,
on the back you'll see that the image is black and white. That's because this is the face of a little,
black and white cathode ray tube pretty much like the one that's in here. You know - the big heavy glass things that
we used to have to haul up and down into our apartments, before flatscreens
finally came down in price? It's a tube probably about yea long goes back here, and then there's the end with
the pins, and the wires go off wherever and there's the high voltage circuitry and the
flyback transformer and everything all packed into the camcorder [sic] body. 'course, with this sort you were just supposed to
look straight into the back of it so that put the CRT comfortably <i>inside</i>
the camera's body. There's another, perhaps more common variety,
that you might be more familiar with. For cameras that could go on your shoulder they would put the CRT out here on the
outside of the camera initially, in these little outboard pods,
like this where the tube sticks out way behind
the eyecup but later they refined that. This here is a 2001 professional studio camera, and this has, pretty much, the endpoint
of this technology. This is also a CRT viewfinder but the CRT is up inside of here instead of hanging around outside the camera. There's a 45-degree mirror in this box here So you look in, and your vision is reflected into
the face of the screen which is right about here. So obviously this, uh makes it much more compact You can put this on your shoulder, look
into the eye cup, but the CRT itself isn't hanging around
outside the camera it's safely tucked away over here. I can show you real quick, on this one,
what this technology looks like. So, by 2001, this is what the insides of
these things looked like. You can see the tube itself is
very diminutive, actually, a good chunk of it is up here,
this is where the part that flares out and contains the phosphor screen is,
it's up inside this little neck here. The anode connection is also hidden up
in that bell, that's what that white wire is. And then you've got your magnetic yokes here, and then at the back you've got
your cathodes [sic]. Then all the high voltage circuitry, the flyback
and everything are all tucked in here. it's a very compact little package. But let's plug this back in, and see
what it looked like in 2001. If we take a look in here, you'll see that the viewfinder image is still
black and white. It's a very nice, very crisp- nicely contrasty black and white but it's still just black and white. Now this was a very expensive, very high end
camera when it came out. this was sold for tens of thousands of dollars about 40 to 50 years after color
television hit the market. So, why is this viewfinder still in black and white? Well, I can only speculate on this part,
because I didn't find any supporting documentation but I think the reason is just that making
color CRTs this small is <i>incredibly difficult.</i> The technology that goes into
making a color CRT is extremely complicated
compared to a black and white CRT The principles behind the black and white CRT
are actually pretty straightforward. There's lots of videos that'll
explain basics of CRT technology but let me just give you the cliff notes With you basic black and white
CRT it's very straightforward You've got a phosphor
screen at the front you have an electron gun
or cathode at the back When you apply voltage to it electrons shoot
forward, hit the phosphor and produce light There are magnetic yokes - electromagnetic
coils wrapped around the tube one makes the beam go up/down,
one makes it go left and right and by steering that around it can sweep
the beam across the screen. By adjusting the voltage at the cathode
to produce more or less electrons you can make more or less light on the screen and by sweeping the beam across the screen
rapidly while doing so, you can produce a picture. The color tube does exactly the same
thing but it does it three times at once There's three cathodes at the back producing
three electron streams and there's three colors of phosphor on the front -
red, green and blue. However, what it doesn't do three times is it
doesn't sweep the beams three times it sweeps them all just once across the screen. Now the reason for that is that as the beams
travel across the screen they have to illuminate each of the three colors
of phosphor in each of the color triplets - the red, green and blue - with the appropriate intensity for that component
of the picture at that specific location. You could try to do this with one gun
but they just can't get them fast enough. As the beam swept
across the screen it would have to rapidly change
intensity to match whichever color phosphor it was over at any given moment. In a black and white television
this doesn't matter so much. As the beam sweeps across the screen
there might be microscopic differences in exactly where it hits the screen -
it might not be in perfect synchronization but that doesn't matter because
your eyes can't make that out. However, in a color tube, the different colored
phosphors are so close together that if the beam isn't in exactly the right spot
when it switches from the red channel to the green channel, it's going to shift color
as it moves across the screen. So to solve this problem they used a thing called
a "shadow mask," which is a metal sheet with a bunch
of little tiny holes punched in it, and as the three electron
beams sweep across the screen, all three are continuously
outputting their color channel: The red gun is doing the red, the green
doing the green, and the blue doing the blue. But when they get to the screen, the shadow mask
prevents each gun from being able to hit the color phosphors that aren't intended for it. So when the red gun tries to
shoot at the green phosphor, it hits the shadow mask instead,
and so on for the other colors. This ensures that each one can only reach its
color, so they don't need to know where they are on the screen, they can just
blindly blaze across the screen shooting out the image without
thinking about where they are and they'll all end up in the right spot. There's a variant of this called "aperture grille,"
or Trinitron - Sony's name for it but it's exactly the same thing.
It uses a differently shaped shadow mask and it uses strips instead of dots of phosphor
but it's otherwise exactly the same principle. Okay, that was the quickest
possible explanation I could do. Taking all of that - the three guns, the three
color phosphors, the shadow mask - and putting it all into a tube
that's only this big, I think might just be beyond
our manufacturing capability at least in the era
when this was made. I've never seen anyone pull it
off, other than the Panasonic CT101 which came out the same
year this thing did and I think it still [was]
quite a bit larger than this. I think it's, like,
an inch and a half or something like that? So color CRTs just never made
it into camera viewfinders. Except this one. This isn't an early LCD, it's not some sort
of field sequential color wheel contraption or something,
this is a single gun color CRT. I can prove this. I happen to have two
of these viewfinders This one is broken, it came off of a
Hitachi model of the exact same camera. You can see these are definitely
exactly the same unit. I'll just open this up here. You can see that although it's much
larger than the last one I opened up all the same parts are here. Here's the tube, it's bigger than the
other one only because it's older, these are the magnetic yokes,
there's the phosphor screen this is all the control circuitry, there's a little
tiny flyback transformer, hidden you can barely see it but it's in there So this is also a cathode ray tube, and there's
the mirror I was mentioning which bounces the image from the front
of the screen out through the eyepiece. Now I can't prove from showing you the innards of
this thing that it only has one electron gun but I can prove that it's a
very unusual type of CRT. If we look up here, in the mirror box,
you'll see in the bottom there's this odd thing. There appears to be a couple little
lenses there and a couple little filters So what's all that about? Well let me button this thing back
up and I'll show you what those do. 'kay, if we take a look
back in the viewfinder here and then I just stick my finger in
there and block one of those lenses you'll see the color
starts to go away. If I stick my finger all the way in, it's gone
completely, there's pretty much no color in there, there's this weird moire
effect but that's it. Take my finger away,
and the color all comes back. What black magic is this? Well, I'm not gonna keep
you in suspense any longer: this is a thing called
a "beam-index color picture tube" it's also known as Indextron,
that's Sony's trademark for it, of course. It's able to produce color in a conventional-esque
picture tube using no shadow mask and only one gun,
using a system of closed loop feedback. Essentially they managed to make a color picture
tube with no more parts in it than this black and
white picture tube. The way they pulled that off is by eliminating an
entire factor from the equation which is the need for precision timing. As I said, if you wanna use a single gun,
then the circuitry in the TV has to know where the electron beam is at all times, down
to within one phosphor stripe of it's current location. If it gets it wrong, if it's off by even a little
tiny bit, just a couple of nanoseconds then it's gonna start spilling
color into the wrong phosphors. Now, normally the way you'd have to do
this is when you send that electron beam flying across the screen, you'd have to have a piece of circuitry that's
able to keep track of where that beam is by just guessing really really well, because the
beam doesn't give any feedback on where it is. By adding a system to obtain that feedback, you can remove all the dead reckoning from the
equation, and that's exactly what this tube does. In order to get that feedback, they take the
normal phosphor stripe order of red, green, blue, and they introduce
two new colors. The first one is an ultraviolet phosphor which
comes before the red in each color triplet. The second one is a different color green that's
in the middle of the normal color green if I'm understanding it correctly. It wasn't super clear from what I read, I went
through some patents and I read some other peoples documentation on
this and it was all very confusing but apparently there's like a special green that
they have in the middle of the normal green. That hump in the bottom of the mirror box has two
photosensors in it, and those sensors have lenses on them that filter them to only
receive ultraviolet light in one and that special color green in the other. Now as the beam sweeps
acros the screen, every time it hits an ultraviolet strip of phosphor,
it produces a pulse in the ultraviolet photosensor and every time it hits that special green,
it produces a pulse in the green photosensor. Those two pulses are what you'd typically call
in electrical engineering a "clock signal" they tell the circuitry how fast the beam
is moving, and when it reaches certain points. Every time the circuitry detects a pulse from the
ultraviolet photosensor, it knows the beam just crossed into an ultraviolet
phosphor and is about to enter into a red one so it can start outputting the
red component of the color signal. Then as the beam passes into the green phosphor, it
produces a pulse in the green photosensor and I believe this basically causes the circuitry to
resonate at the frequency of the beam passing through the phosphors. With the circuitry knowing when the beam is going
into a red phosphor and knowing how long it takes for it to get to a green phosphor, it's able to
pretty much know how quickly to cycle through the colors as the
beam goes across the screen, in order to land every
color where it belongs. And that's pretty much it.
It's not actually a very complicated system. It kind of makes you wonder why
they never thought to do it before. Well, apparently they did think to do it before,
they thought to do it in the sixties and it didn't work. They kept trying and trying and trying to
get it into a finalized product but as far as I know, they never got it into
any consumer products other than this thing- A little tiny portable
television that Sony made- And a big honking projector that
Sony made with a Betamax deck in it. And other than that this never really made its
way into anything, and I'm not super sure why. Probably I would guess because the actual need for
small color tubes was not really that big a deal, and in larger tubes they had just figured out how
to make aperture grille really well so TVs looked pretty good by the time
anybody had figured out how to make this work and no one really needed
to put in the extra effort of adding these extra semiconductors
and this complex timing circuitry. I could be wrong, but at any rate
it never happened, so it's moot. And hey, who cares,
because it also doesn't work very well. If you compare the quality of this viewfinder to
the quality of the one in the 1993 LCD camera it looks a lot better
in the LCD camera. This kinda looks like crap. It's one of those technologies where they pulled
off this incredible feat of engineering producing a device that no one actually wanted
to use because it still sucked. |It's incredible that it can do it,
but it still doesn't do a very good job of it. So, more than anything,
it's just a curiosity. If you're familiar with CRTs and are impressed
by one that's able to pull off the seemingly impossible, then this thing is neat but otherwise, yeah, it's not
really much to write home about. There is however one remarkable side effect of
this system which no other CRT could claim and I find very impressive although
it's kinda hard to demonstrate. This is a magnetic retriever tool, and you probably know that you
shouldn't hold magnets near CRTs. Now, that advice is
a little nuanced. See, if I put this magnet up against this black
and white television, you can wave it around and, you know,
it kinda messes it up but when you pull it away, it goes
away, there's no lasting damage. If we do this same thing with the color
tube though, it distorts the colors horribly and when we pull it
away, they stay distorted it puts this big
ugly bruise on here and it'll just stay there indefinitely - at
least, until we hit the degauss button. Now, the reason this happens is because in the
black and white television when you put the magnet up there, the electrons
start bending around the magnetic field but as soon as you pull it away they go back to
normal - they strike where they're supposed to. There's nothing to retain the magnetic field. In the color television however,
the aperture grille in this case or the shadow mask if it was that style,
is made out of a ferrous material. That means it can hold a magnetic
charge, or flux state. So, when I put the magnet up there,
it distorts the electron beam and since those electrons are
being distorted <i>after</i> they get past get past the shadow mask or aperture grile,
they continue to get distorted on their way to the screen,
which allows them to hit the wrong phosphors. That's why we see red turn into green and green
turn into purple and so on because it's shifting them from their appropriate
phosphors over to the color next to them. And then when I pull the magnet away, it leaves
an imposed magnetic flux on the shadow mask or aperture grille. In other words, it turns the aperture grille,
in this case, into a tiny permanent magnet. So even though my magnet is gone,
I've magnetized part of the television and now when the electrons are streaming towards
the screen, when they pass the aperture grille they get deflected by the grille itself. When you press the degauss button on the TV
it corrects this by generating an alternating magnetic field that essentially resets
or neutralizes the magnetism of all the metal near the front of the screen. Now let's do it to this one! I'll admit it's kind of harrowing putting a
powerful magnet next to an incredibly rare and priceless- - not priceless - -but, still pretty rare and special
tube, I mean, what if I damage it, right? But I'm gonna go
ahead and do it. Okay, so, here we are, and now I'm going to take
the magnet and put it right up near the face and you can see that it bends
the heck out of the picture and it does distort the colors but then when I pull it away,
everything just goes back to normal. The colors don't stay distorted. Now the reason for that is that there's no
shadow mask, and there's no aperture grille. There's nothing to
retain the magnetic flux. So, as soon as I've pulled
the magnet away, the colors all steer right
back to where they belonged and there's no persistent magnetic
field to continue distorting them. I know it's less punchy than if I could put this
straight up against the screen it's just really hard to get
in there without damaging it. The other thing that's kind of hard to make out
on the cellphone video- it, it shows up a lot
better to the human eye is that although the colors do
distort, they're not actually changing hue like they are on this one. The greens aren't necessarily
shifting into reds and so on. It's sort of an
optical illusion. When you look at it with your eye, they actually
stay the same, they just start to lose saturation as the magnet gets closer. That was actually a selling point of these CRTs,
in the only application they were apparently used for, although I haven't found much
information on this, which was, ostensibly, military applications. By the nature of their design, this type of tube
is more resistant to magnetic fields because, since it decides which color is where based on
feedback, when you distort the electron beams path with a magnet, the pulses are still
being sent back to the photosensors. So despite the fact the electron beam isn't
landing quite where the circuitry expects it to be the circuitry doesn't care, because rather
than guessing, it's relying on those pulses coming back from the photosensors to tell
it which color to send out next. So, sure, you're making the beam go faster or
slower or curl itself around or whatever, but, it's still tracing a
path across the screen so every time it hits an ultraviolet
strip the device starts putting out red and every time it hits a green strip
the device starts putting out blue. It's a pretty neat trick, and if I'm ever able to
secure myself a larger Indextron so I can show you this at a larger
scale where you can maybe see it, I'll make sure I
put up a video. I have a eBay saved search for every
single Indextron product ever made. It is by far the coolest damn
thing I've ever seen a CRT do - any other tube I'd done that to I would
have had to get a tape demagnetizer out to try and get it back to
something approaching normal. It's just a really
cool party trick. Other than the magnet trick though and the fact
that it is technically rare and technically clever, like I said, there's not
a whole lot to write home about So, I will just tell you a short story about this. I actually have two of these I've got this one, and then the
one that came with this viewfinder which was Hitachi branded, that I picked
up at a Goodwill for like eight dollars. Brought it home,
plugged it in, didn't work and when I looked at the front of the
viewfinder, I saw <i>"Color electronic viewfinder,"</i> and I thought that it meant,
<i>"Color camera with an electronic viewfinder."</i> It never occurred to me that the
viewfinder itself might be color. So I just put it in a box and I
stuck it in my storage unit and ignored it for like a year and a half. And then when I was doing inventory a couple weeks
ago to see what cameras I had I came across this one and I happened to
google it and saw something mentioned it had a color viewfinder, and I thought- <i>nuh??</i> I knew that couldn't be right because there was no
technology that could make a viewfinder that small, so I dug it out and
I brought it home again and plugged it in,
and it still didn't work and then I saw those humps in the bottom
of the viewfinder and I thought, <i>no...</i> 'cause at this point I'd heard about the
Indextron - I knew what a beam index tube was I just recently read about them for the first
time and so I thought,
"there's only one way they could have done this- -but it can't be that." I did not buy a beam index color tube and just
throw it in my storage unit and forget about it for a year - broken or no, there's <i>no way</i> that
happened, right? I did do that! I guess it just goes to show that there's value in
Googling virtually anything you have looking it up on Internet Archive,
looking it up in old magazines to find out what people
wrote about it, because you never know what
you're going to discover. After I discovered the other one didn't work I
went to eBay and looked up the RCA version
of the same thing and I found like six of them for like forty
dollars a piece so I just ordered one, hoping it would
work, and it arrived and it did work so, I'm glad I was able to demonstrate it for you. So that's all I had,
it's not a very complex topic. Maybe I'll talk about the rest of
the camera someday, I don't know. It's okay, it's kind of interesting, but the
viewfinder I think is far more novel so I figured I would tell you all about that. If you enjoyed this it'd be cool if you could
throw me a couple bucks on ko.fi or subscribe to my channel,
any sort of feedback like that makes it a lot easier for me to stay
motivated to keep making videos. Anyway, thanks for
watching, have a good one!
I love my Camry. It’s manual.
I don’t have much interest in old camcorders or CRTs but this guy clearly has a passion for this stuff and was actually worth the watch
Gotta appreciate the pioneers of this kinda technology.
There must have been a lot of R&D in getting a CRT that small with that kind of tech.
I love old tech, anything with a tube, straight forward YouTube videos without pun, and you. Very cool stuff. Thanks
"It's one of those technologies where they pulled off this incredible feat of engineering, producing a device that no one actually wanted to use because it still sucked." The funniest thing I've heard all day.