All language subtitles for 2. How Light Behaves

How does light behave?

What is light?

What is it?

Is it some airy-fairy atmospheric thing that

just floats around?

How do we shape it?

How do we use it?

How do we make someone look pretty?

How do we make someone look more dramatic

with light?

There are so many different ways, but this

is the first step of my five-step

process to a well-crafted photograph.

So let me go through it.

What affects the quality and quantity of light?

Well, there are many factors.

Of course, it's the size of the light

source.

That'll affect the quality of light.

The intensity, it's the power of light.

The distance of the light to the subject,

that's going to affect it as well.

Your camera angle, because you can have the

exact same light, but the minute you change

your angle, it's going to appear quite different

because you might be exposed to more light

or more shadows and so on and so

forth.

And then, of course, you've got your light

angle, which we've just discussed.

Now, I am going to get into a

little bit of the science behind light.

You may have heard of the dreaded inverse

square law.

What does that mean and how does it

affect what we do?

I'm going to quickly touch upon the mathematics

of it all, but I'm going to mainly

get to the heart of what it's all

about and why you arguably should need to

know it.

So let's go through it here.

Now, this is going to confuse the heck

out of you, so don't be intimidated by

it, but basically, what is it?

The inverse square law is the intensity of

the light, the power of the light, equals

one over the distance squared.

Now, I'm not a mathematician.

I did a bit of algebra.

I wasn't that good at math, but we've

done some homework here for you and put

it in sort of simple and layman's terms.

So let's say, for example, we've got the

distance squared, so one over the distance squared.

That is the distance.

Let's say it's a foot, okay?

One over the distance squared.

That distance squared, okay, is one, okay?

So one times one is one.

One over the distance squared, two by two,

is four, and so on, and so on,

and so on, and so on.

So why I've greyed that out, so ultimately,

if we work out what the distance squared

is, okay, now we have one over one,

one over four, one over nine, as in

one, a quarter, a ninth, a sixteenth, and

so on.

When you translate that into the percentage of

light, what happens is we've got 100%

of light.

So let's say the distance from the camera

to the subject, let's say that represents 100%.

We have to start somewhere.

So let's call that 100%.

So we've got there 100%.

This is the most important factor, because you

might have been taught this and think, why

do I need to know it?

This is just a pain in the butt.

What do I do?

Well, this is the biggest part of this

equation.

All you simply need to know is, once

you double the distance from the actual light

source to the subject, you actually lose up

to 75% of that light.

But do you see how it actually diminishes

very, very slowly here?

So double the distance, and you lose basically

three quarters of your power, and that is

a big factor.

You need to know that.

So when you've got either an on-camera

flash or an off-camera flash, whether you

have a reflector or whatever, you double that

distance, you lose 75% of that light

to the subject.

So hopefully, that is hopefully the easiest way

you've ever been explained the inverse square law.

But what other factors come into play when

we talk about it?

Well, let's go through it.

Not only are you reducing the power of

the light, you're actually losing the, well, actually,

you're increasing the size of the light as

you go further away, which is almost counterintuitive.

You almost might think the opposite.

It's funny because the inverse square law, and

I was doing a bit more homework because

I've only really learnt it and taught it

in relationship to light.

But as I did some more research here,

it actually applies to the gravitational force, electric

field, of course, light and sound, or radiation.

So it's quite fascinating that these laws exist,

but they help us to understand everything a

little bit better.

So we're talking about the light source, and

let's say this little line here represents the

original distance from the light to the subject.

So what happens is, although this is a

certain size, this is actually small, let's say

small, it is what it is, the size

is what it is.

Once you go further away, you can sort

of see how I've actually used these colours

to represent that it's almost desaturating, you know

what I mean?

Like we've got less power, and of course

we do, because here we said the distance

from the light to the subject, that represents

100%.

When we double the distance, okay, so original

distance, we double it two times over here,

now we're actually reducing that power, like I

said, by 75%, but we're multiplying it by

four, so it's actually spreading out, but it's

losing its power as we go further along.

So ultimately, to basically sum it up in

what we discussed, again, remember, double the distance

from the light to the subject, you lose

75% of that light, and of course

as you go further away, the more it

spreads, but of course the intensity decreases.

Once you understand those things, then it makes

it a little bit easier.

I'm not really even suggesting that arguably you

go in to a shoot with these mathematics

and freak out, you just need to know

those basic fundamentals, so that you can understand

how the light behaves, and know that when

you're turning your flash on, like what's going

on, I just, I moved my, you know,

my subject, you know, one metre back, and

all of a sudden I've got hardly any

power left.

Well, that's because of the inverse square law,

and what I want to do now is

I'm actually going to show it to you

in more of a practical method, by shining

a flashlight on a piece of paper, and

let's see if we can prove this theory.

Light travels in straight lines, so each ray

of light has its own path until it

deflects or bounces off something, which continues, of

course, on another straight path, and so on,

and so forth.

So let's look at our drawing here.

We've got the light source right here, light

travels in straight lines, it doesn't get squiggly,

it doesn't wrap around, or anything like that,

it'll just go on there, and then it

will deflect, if it has something to deflect

from, and it will keep on bouncing accordingly.

That's a fundamental, but we just need to

understand it's pure physics, this is what it's

all about.

Now, the intensity of light reduces as the

subject and light are moved further apart.

That's a pretty obvious one.

If this is, you know, if this is

your subject, and this is your light source,

as they get further apart, the intensity will

reduce.

Now, let's prove it.

So let's say this piece of paper represents

the subject, and then let's say where the

light is right now represents 100% of

that light, okay?

Of course, we need a starting point.

Now, we just established that the inverse square

law suggests, or actually, factually says that if

we double the distance from the light to

the subject, we reduce the intensity of light

by 75%, so we've just shown you that.

Not only that happens, so we're reducing the

light by 75%, but we're also making it

bigger.

If we go to the slide here on

the screen, you can see that the number

one, that sort of orange looking box there

right in front of that light source, that's

the intensity of the light there at 100%,

but when we double the distance, now we're

multiplying that area that the light is covering

by four.

So let's prove that in actuality here with

our example.

So you can see that if this represents

100% of that light source, if we

double the distance, then you see how now

we're getting a bigger light source.

The problem is we're getting a bigger light

source, but we're losing the power or the

intensity.

To go back to our analogy of water,

so right now we've got this small hose,

and it's quite sharp, and it feels quite

tough on the skin.

When we go a little bit further back,

it actually feels larger, so we actually feel

more water on our body so to speak,

but it's less pressure.

Now yes, there are a couple things that

come into play here.

Now if you look at that diagram back

there again, so you've got, if it's with

a speed light for example, you've got the

bulb inside the flash head that if you

zoom it in or out, the spread of

that light becomes different.

So you have to understand, although that this

is an actual proven principle in physics, you

have to understand it's going to be a

little bit different depending on the light source,

and in this case, in the example that

I'm giving you, the flash head.

So let me show you this now as

well.

So you see, actually let's see this, so

let's say for example this is the widest

that we can do the flash head, all

right, so the zoom, the flash head within

the actual unit is right at the end

giving us a wide spread.

It looks small now because it's close to

the actual area.

Now I can zoom this, and do you

see now how small it is?

So when the actual flash head comes closer,

then what's on screen right now is maybe

not exactly correct based upon that flow.

So again, depending on the pressure of the

light, the intensity of the light, if you

can zoom the flash head, then arguably that

particular diagram that you're looking at now will

be wider or narrower depending on those things.

But again guys, remember that as you bring

the light source away from your subject, it

gets bigger, which is fantastic because we can

say, you know what, if I need a

bigger light source and photographing a big group,

I just bring it further away.

The problem is I need more pressure, as

in more intensity of light to illuminate everything

that I want.

So it's a bit of a give and

take thing.

So remember that, practice that, and have some

fun.

So remember this, the larger the light source

relative to your subject, the softer the light.

So here we have a good friend of

mine, Rainy, she's actually against the white background,

and it's very, very cloudy, okay, so we

basically have a very, very large light source.

Because it's basically so big, it's very soft,

because you can think of it like if

it's not the sun, the sun isn't the

light source anymore, the clouds have diffused the

light, and now the whole sky, the clouds,

everything is the big light source.

So the transition from light to shadow is

not so great, it's quite soft, it's less

descriptive, and all those different things.

Now let's look at the difference.

The smaller the light source relative to your

subject, the harsher the light.

So now the clouds have gone away, and

now we basically have the sun as the

light source.

Now people think the sun is big, it

is per se, but it's quite small relative

to my subject.

So arguably it is a small light source,

and because it's so small, the harsher the

light, as in the more contrasty it is,

you can see the shadows are deeper, we've

got a very defined shadow against that sort

of white background there as well, so it

gives us a completely different look.

So if you look at the comparison, there's

a large light source, there's a small light

source, and that could be likened to basically

anything.

It could be a big window or a

small window, it could be a larger flashlight

or a smaller flashlight, it could be a

big softbox or a small, and so on

and so forth.

If you look at, this is actually Melissa's

40th birthday shoot, yes she looks amazing for

40, very very proud of her and her

heart and her beauty.

This is open shade, it's quite overcast, so

we have a big light source, it's very

soft, okay, so it's very complementary.

You might be using this kind of light

source if you want to have maybe some

challenging skin and you want to soften the

skin, maybe you have maybe aging parents or

grandparents and you find open shade is really

really nice, so therefore this might be really

good.

But then when the light source is smaller,

let's say there's no cloud now, the sun,

so the sun is small relative to clouds,

now the light source is smaller, we get

it more contrasty, it's more sharper, we've got

sharper edges, we've got the transition from highlight

to shadow is more abrupt than before, as

you can basically see.

So what we're trying to do is just

give you some fundamentals that you can take

in your next shoot, whether it's a wedding

or a portrait, whatever it may be, but

these are fundamentals that you basically just need

to know.

So let's talk about this one, the closer

the light is to the subject, the darker

the background.

So this is basically shot in a hotel

room, this was a dark background, I think

it was a black background, but as you

can see, just off the actual perspective of

this photograph is a window.

Because she's quite close to it, the background

becomes darker, because I have to expose for

her, as in get detail on the brightest

highlight in her face, which forces the background

to pretty much go pitch black.

Now if I change my angle, so now

I've got her from the, let's say for

example the bedroom window was basically here, and

she was facing this way in a profile,

now she's over there up against this grey

wall, so the further away the light is

from the subject, the lighter the background, because

of course the the value of exposure between

the bride here and the wall are quite

similar, so therefore we have that effect.

If I wanted that background darker, I simply

get her closer to the light, expose for

her correctly, as in I want detail on

the brightest highlight in her face, then of

course that background, although grey, might appear a

dark grey or possibly even black depending on

how far away we are.

And it's amazing too that all we have

to do is just change our angle, so

she stayed there, I changed my angle to

camera left or her right, and then we

get this photograph.

So there is so much to photography that

you can't take anything for granted, and there's

no absolutes, that's why in many occasions I'll

say the larger the light source relative to

your subject, the darker the background and so

on.

Well it depends that, see we could be

using a large light source, but we could

be shooting on the fringe of it, which

now becomes a small light source.

So if you look at these three photographs

of the same girl in the same room,

although this was quite a large light source,

it was a large window, I had her

on the fringe of it, and really we've

got a tickle of light on her face

and a little bit of her ear, we

turned her shoulders, so only a hint of

her shoulders in light, but the rest is

in shadow, well now it's sort of become

a small light source.

And of course you may recognise that, that's

a part of the banner behind me there

as well.

So we need to practice these things to

sort of really understand how we bring out

the best in our subjects, and what kind

of mood we're trying to create and things

like that, and of course we're going to

discuss this further as well.

So let's talk a little bit further about

how light behaves.

Remember the closer the light source is to

your subject, the sharper the shadows on your

face.

So if you want something, or your subject

to be more dramatic, bring the light a

little bit closer, and then you've got that

light and that shade that's going to be

a little bit more contrasty.

The further away your subject is from the

light source, the softer the shadows.

So for example if you're photographing parents or

grandparents, and you want a softer transition, you

want a little bit of modelling as we

call it, making a face look more three

-dimensional with shadow, but you don't want it

to be so abrupt between light and shadow,

bring the light further away and it's a

little bit softer.

A good example also is if you're photographing

let's say a plus-sized bride, who you

might want to use shadow to cut in

and actually make her look slimmer, but she

also maybe has bad skin.

So that shadow makes her look slimmer, but

it's not so abrupt between light and shadow,

but the softness of that light is actually

going to make her skin look a little

bit softer.

So there's a good example of that in

action.

Remember smaller, harder contrasty light means a transition

of light to shadow is more abrupt, which

creates deeper shadows.

You might actually recognise my work, I love

deep shadows.

I just think they're just so dramatic, very,

very cool and I'm not always after absolute

perfect detail in blacks.

No one said that you have to have

detail in blacks.

Maybe if you go to a competition, you

will often hear a judge say, well I

don't see any detail there.

Quite simply, there is no perfect exposure, there's

no perfect light.

It's really, it's basically perfect or the execution

of your desired result.

Do you want deep shadows?

Do you want black in those shadows?

If that's what you want and that's what

you execute, then you've done it, no problem

at all.

Remember larger, softer light means a transition of

light to shadow is more gradual.

As we sort of previously discussed, you saw

those photographs of Rainy, my wife Melissa, where

it was a little bit softer, blended in

a little bit.

Some people like that soft look and depending

on the body type, the shape, the skin

type, these things come into play and that's

really, really important.

Ultimately guys, remember this, we often say that

lighting is the most important thing technically in

a photograph or in photography per se, but

really it's actually the opposite in my humble

opinion.

It's a subtraction of light that creates luxury,

depth, mood, dimension and shape and form and

all these different things.

That's what it's all about, is where do

you take away the light?

Once you take it away and we'll discuss

this in future segments, it becomes very, very

beautiful.

You start to see a beautiful three dimensional

form and shape, you see texture, all these

different things.

We're going to learn how to almost light

something completely and then take away light and

that's what's going to create that beautiful mood

and make images just pop off the screen,

pop off the print and just look gorgeous

as you're looking at a beautiful album.

Bear with me, we're going to simplify it

even further.