All language subtitles for 02_Quick_breakdown_of_a_camera_and_light_physics

in this lesson

we're just gonna quickly go through the

elements of the camera

as well as a few terms that we're gonna be using

about the physics of light

so this is just a quick primer

into some of the words we'll be using

now you probably know some of this uh

this is a cut away of a camera

and I'm probably not gonna be able to redistribute

these images

so a camera

uh no matter if it's for photography or for cinema

is all about capturing light

and it does that with essentially three main pieces

at the very back of the camera

we have in the digital world a sensor

and of course in the film world

we have the actual film

now an important word we're gonna be using about

the censor or film is ISO or ISO or

International Standards Organization

and in the digital world

it's sometimes called sensitivity

now we're not gonna be going over this in great detail

until the lesson

and even then we're not gonna go over it in again

a great amount of detail

if you wanna learn more about ISO

aperture F stops

and some of these other terms and techniques

that we talk about

we actually have

visual guide videos describing them in much more detail

so on our website

you can go to training

Visual guide

and these are post produced lessons that we

spent quite a lot of time creating

and you can see we've got visual guides to many things

so aperture or f stop

we have a visual guide for that

we have a visual guide for ISO

as you can see

we also have visual guide

for some other things we're gonna be talking about

such as chromatic aberration and refractions okay

back to the camera

past the sensor is the aperture

and this is a hole that

uh controls the amount of light that hits the sensor

so this is the five sided

six sided piece

um or shape that blocks out light

and this is inside of the lens

so each lens has a

different kind of aperture

the shape of this actually defines the

Boca or the depth of field shape

uh that we see in out of focus areas

but again we'll cover that later on

and we have the other elements of the lens

or the pieces of glass

now you can see here

lenses are actually quite complex

uh we I can owned I think

12 different pieces of glass inside this single lens

and that can go up or down

depending on

how we're using the lens or what kind of lens it is

and these lens elements is actually where

uh some or most of these

optical aberrations or these problems

arise because

uh as you no doubt know

interactions between

different elements

can be quite complex

and as you can see

the shape of these

is unique for each of them

so let's not talk about how

light interacts with objects

now your probably familiar with

the first interaction

which is reflection

so the light is hitting an

object and bouncing off

you've obviously seen a mirror

so you know reflection

so reflection can actually happen in between

any of these elements

and that's what causes um

things like lens flares

filter flares

ghosting and so forth

they actually spend a lot of time and a lot of money

trying to make sure these lenses are

as anti reflective or not reflective as possible

but we still sometimes see it

and it's an important part of this interaction

after reflection

we have refraction

so whenever

light enters a

semi transparent

or transparent

material or object

it tends to bend based on

the outside

so based on where it's coming from

and then where it's going

now as you can see here

the bending of the light can be quite extreme

and if we were

forced to calculate

how the refraction of all of these

elements added together

uh we would no doubt

not have a good time

so refraction is another thing that is

very delicate

and can cause some problems

uh inside of a lens

but again these are

very finally

mechanically engineered

to uh refract

the light in a way

that hits the sensor correctly

and finally

we have diffraction

and what diffraction is

or what it says is

that light or

any kind of wave will begin to spread

out if it is

forced through an opening

now since our

aperture is a hole that we

are forcing

the light through

it begins to spread

out before hitting

the sensor now

uh what does

white light

spread out into

well it spreads out into

our color spectrum

and we can easily

see that with a prism

we can see here

white light

comes out of a prism

spread into

the rainbow of colours

so the diffraction of light

or the bending of light or the

uh dispersion

or interference of light

also plays a

very heavy role

inside of optical

aberrations

now those are

essentially

all the terms we're gonna be talking about uh

we're of course

gonna go deeper into these

as we go through

each kind of optical aberration

now we're going through this course from

the outside in

so we're gonna start with aberrations that happen

in the real world

or exterior

to the lens

and then we're gonna be

moving through

the lens into

things that happen

uh with these elements

aberrations that happen because of aperture settings

and finally

aberations that happen

at the sensor level

so to end this

we're gonna be talking about things like film grain

and sensor noise

so starting

at the outside

we'll go into

the next lesson

begin talking about

vignetteing

now let's just go through a quick recap

cause I know we went through this pretty quickly

cameras are three pieces

essentially

a sensor or film

which captures the light

an aperture

which blocks

part of the light

and the lens elements

which bends and

refracts the light

so that it hits

the sensor correctly

now the light is

not simply just

moving through

the lens normally

light is a complex phenomenon

so it is reflecting

refracting or bending

as it moves through

each element

and it is also

diffracting

or being spread

out by each element

so what this ends up as

is a lot of things happening to this light

from when it

enters the camera

to when it hits the sensor

and so we're gonna be talking about

each of those different kinds of aberrations

so we can add them into our

own footage

or match them

with our composites

so let's jump right in

and take a look at

how we're gonna

add vignettes

and what the

two kinds of vignettes are