Why is the green screen green
Why Are Green Screens Green?
hey everybody welcome back to a think
tank it's Hannah Kristen and Jonna Daryl
and today we're talking about green
screens now we're on YouTube and there
are a lot of youtubers a lot of people
in any kind of online or streaming video
that use either all the time or from
time to time green screens that's
something that because of that people
have gotten to know but they don't
necessarily know exactly how it works or
why you use it or some of the
limitations just to clarify we are not
allocating we're not on a green screen
not on a green screen this is all
physical stuff that exists um I
understand that it's really brightly lit
but it's not actually a green screen we
do once a week we sometimes shoot in
front of a bunch of TVs yeah again not a
green screen yeah but let's talk about
what a green screen is or green
screening also known as chroma keying
that's the inside baseball term that is
the process of isolating a single color
or brightness value in an electronic
image and then making that value
transparent in post-production allowing
another image or footage to be placed
beneath the color that's been blanked
out so what does that actually mean in
practice it means if you imagine imagine
if it was all green behind us and then
it's me and Hannah you tell a computer
program to look at each little part of
the image like a pixel and to the extent
that that pixel matches green or
whatever color you choose I want you to
make it transparent and I imagine if
there was an image behind all of that
that now transparent green parts
wouldn't you be able to see it and so
you'd see through to whatever else is
there a picture of the Andes or outer
space or back then exactly
and that explains because it's that to
the extent that it's green that explains
why in bad green screening you see like
a flickery sort of like effect it's
because the lighting meant that it's not
all equally green it's perfectly lit
then it will be gone and it'll be a good
green screen or a good key key hang out
is the term you use but if it's not well
lit then it gets all like grainy and
wavy and it doesn't look real yeah and
you guys have probably done this on a
more two-dimensional level if you have
ever used like Photoshop or something
like that you can set a certain color to
be transparent
something like that so it's a very
similar sort of situation yeah yeah and
in Photoshop you can set like a region
which theoretically would be great if we
could do that but because we're moving
it's just too complicated especially
like if you have like like I have hair
you know if my hair is curly or
something then you could see through it
and make it becomes yeah bit more
difficult and so the reason and the
reason that that happens is that there's
little tiny gaps in your hair and
lighting effects hair in a particular
way that it messes with the color and so
some of the hair gets kind of greenish
off the green screen and some of the
green gets a little bit brownish off the
hair and that's why if you have
complicated hair it doesn't look as good
on me but John why is it green well like
I said you say I want it to the extent
that it's green you could pick any color
you want but look at me right now
what colors do you see a lot of white I
understand I'm pale but there's also
blue there's Browns there's a little bit
of red in my skin because I don't take
good care of myself and I'm pale so that
those are the sorts of colors that tend
to occur on people and especially and is
most important in the skin because you
can like imagine if I was wearing a
green shirt I was on a green screen the
green shirt would be invisible you'd see
through it you can tell people not to
wear a particular color of shirt but you
can't control necessarily what color
their skin is and human skin doesn't
have a lot of green in it unless they're
really sick I guess and so you can
remove green without affecting this but
if you were to remove red or orange or
yellow then the skin would start to look
weird and parts of it might be a little
bit see-through which you would not
right now that's not to say that
everybody does use green there are blue
screens as well and if an image like a
costume or an outfit has green in it you
would then have to use something like
blue yeah they were saying that in
Spider Man when they had like the Green
Goblin or whatever his name is they
would use they did use a blue screen
yeah cuz he's all green yeah and shiny
and everything yeah they obviously went
to after spider-man's he has blue on
hisses yeah not a lot of screens for
them if you keep moving the screen and
I'm messing around yeah yeah and
theoretically you could use other colors
those are by far the most common
and yeah so there are there are
limitations if you were in a huge a
YouTube context you wanted to use it you
would have to control the colors that
you wear it has to be shot with a good
camera because if I hurry you have to
have good lighting and it makes making
the video take longer once you're
finished shooting that sort of process
of getting rid of the green is really
hard on computers and takes a long time
which is one of the reasons it's not
more common that already is some people
like video game streamers you'll notice
that they'll have themselves in the
little corner of the screen it's just
them they have a program that does that
removing the green in real time as they
shoot which saves you a lot of time
rather than doing it in post-production
interesting and you guys if you watch
local news ever watch up for the
weatherman because they'll never have or
whether women because they'll never be
wearing green exactly and that's how you
know so some of them might be in front
of a big a big screen with the actual
image but the vast majority are on a
green screen and those they're limited
in their color choice but thankfully
green isn't that popular color to wear
anyway this works out that way anyway if
you have any other questions about green
screening why people use green screen
some of the limitations it's something
that we find interesting I've done a lot
of research into so feel free to post
those questions down below I'll see you
next video
