Kind: captions
Language: en
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 buddies
gonna show me Richard they're cool 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
what's 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 Bane 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
so we have to jump forward to 1884 and a
23 year old German University student
named Paul nip cough he patented what is
called the nip cough disc 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 skin you would put a light
behind this nip cough disc 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 dip called disc
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
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 gold mark 1 in honor
of dr. gold mark 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
trina-- scope so named for its three
cathode ray tubes one for each color and
their images were combined with prisms
the downside of a trina-- scope 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
then fifteen thousand frames per second
a lot faster really to be able to see
this clearly and so I am using the
Phantom v25 12 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've used 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 videotape 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 telus inni the picture doesn't look
right the 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 an
but we've come a long way since then
miniaturizing the tape stand in two 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 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 3 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 that 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 and H for
sponsoring this video