All language subtitles for 03_Mechanical_and_natural_vignetting

in this lesson

we're gonna learn about vignetteing

both mechanical and optical or natural

so here we have our camera image again

now if light is coming through the camera directly

straight on

it has nothing in the way

so all of it hits the sensor

however depending on the shape of the camera

the shape of the lens

and whether or not we have a lens hood

or any filters on the front

greatly affects how the vignetteing will appear

now the first kind of vignetteing happens when

the lens hood or the lens is improperly mounted

and that is

literally light is being blocked by a physical object

so let's jump in a new

can see how we can do this

so I've opened up 0

3 underscore begin

and I should know right here at the beginning

that you can do this really in any application

I'm just going to be showing how to do this in nuke

and we can see here we've just got a very basic setup

we've imported our background sky

a foreground

merged them together

and then I've cropped it

in this case

we decided to use a 3D render because it is

completely free of any optical aberrations

so we can see these applied

using a sort of a blank canvas

now you can use any footage

any photograph

really any kind of image you want to follow along

or of course

you can take a look at these files

and follow along with this sequence okay

so the first thing we have is a mechanical vignette

and this is really easy

let's just drop in a roto node

and let's just grab something like the ellipse

and drag it out

and I'm gonna hold shift to create a circle shape

because most lens hoods

well I should say circular lens hoods are circle shaped

drop that in there

and let's change our roto color to black

so I'm gonna jump over the shape

and let's call this our mechanical

uh vignette here we go

and all we need to do is merge this over our crop

so I'm gonna select the mechanical vignette roto shift

select the uh

layer or the import

and here we have our merge

and this will essentially show us

the vignette

now we're not seeing it

and that's because we're

not sending out an alpha channel

so let's jump over here

back to our vignette

and make sure we're sending out a solid alpha

and let's invert it

now this is essentially a mechanical vignette

what happens is that something is literally

just physically blocking the light

and really you're not gonna see this in the field

and you probably shouldn't apply this to your comps

this means that something catastrophically

wrong happened while you were shooting

that you were literally

something was blocking all the light

and we can make this a little bit nicer

by giving a little bit of a feather here

but in the end

we are still just blocking the light

and so we get this kind of an effect

so again this is a mechanical vignette

and it's very rare to see this in the wild

what's more common is the natural

or the optical vignette

so I'm gonna hit spacebar to return to this

and I'm just going to

break these off

I'm just going to uh

cut them and move them over

so we can take a look at an optical vignette

and an optical vignette

if we take a look at the physics of this

happens uh when light hits at an angle

so this light

uh will partially be

a mechanical vignette

for this area here

where the light is literally being blocked

but light that comes in from the edges of our lenses

will actually lose more power

then the light that goes through the center of our lens

so you can see here

the thickness

of our lenses on the exterior

edges are much wider

and so that can cause

more loss of energy

and that will give us a nice

softer vignette

so again we could drop in a roto node here in nuke

so when I hit the O key again and again

just drop in an

ellipse tell

I'm gonna give it a more

oops a more natural shape

if I hit 0 to turn my overlays back on

something like that

and gonna come in here and again

do the exact same thing

give it a black shape invert it

shift hit m

and merge it over

and we should see

as long as we go back and fix this alpha

is a similar thing

but now let's

really feather this out

so let's give this a

ridiculously high feather

and we can of course pull this back just a little bit

we do not want to

be able to see black at any point

so we might even need to bump up the

the feather to something like 300

and what this is gonna give us is

just a little bit of soft fall off along our edges

so let's take a look at this

and we can see that it is very

subtle effect

uh it's not something that you should

uh be able to

see or be able to

um visibly see

unless you're going for a really

old film look

because most cameras

have only a very

subtle vignette

now this is a simple vignette

I prefer to really

uh give it a slightly

more complex one

so another way to generate a

nice vignette is to drop in a few

radial notes

so let's drop in a radial

and take a look at this

and this is just

again sort of an

ellipse shape

so what we can do is we

can take this

and let's just make it a

big shape here

alright something like that

copy paste that

and on this new one

let's change

the shape again

and all we're doing is

layering uh

complexity or

layering inconsistencies

and so this is gonna give us

slightly more natural look

so just duplicate this again

let's move it over

scale this one up a little

scale it out

and again vignettes

are kind of

unique to each kind of lens

so you can of course

take a picture with

your lens and

other flat surface like a

white background or a

green screen

to see what kind of vignette

your lens is giving you

but in this case

I'm just going to

create a nice

replica okay

so here we have a

few radials

sort of on top of each other

giving us some

interesting fall off here

and now again

all we need to do is merge it

so I'm just gonna grab this merge

and instead of

the overstate

let's actually

use a multiply

let's go over to multiply

and we can see

that's a little bit much

but luckily

in our merge

we have our mix

so we can of course

dial that back

however we want

and so again

this just gives us a little

bit more of a natural

uh fall off

our natural

vignetteing

and some vignettes

uh or some lenses will actually

add a hotspot in

the center um

but this is usually at very

low aperture

so if your lens is

completely wide open

you may get some hotspots

and we can actually do that by

changing this from multiply to overlay

and what we're gonna

get is a slightly brighter

interior so

you'll see here

it's a very

again a very

subtle effect

but the edges

have darkened

and the inside of

our lens has brightened up a little

a little bit again

this mostly happens

at very low aperture

so if you know

you're wanting to go for a

very wide open look

you can keep this on overlay

which will brighten up the center

or change it to multiply

for a purely

darkening of a vignette

so vignettes are

the first stop on

our road to getting

realistic camera

effects that is

of course when

the light is actually either a

mechanically blocked by something

usually a lens hood

that is too large

for the lens

or be the natural light fall off

that happens

on the edges

of our lenses

so you can apply that in a

few different ways

so in the next lesson

let's take a look

at filter flare

or reflectional flares

and how we can create those

inside of nuke