Exposing with a flash!

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description

A no-nonsense guide to learning how to expose correctly and creatively for hot shoe flash.Whether you are a professional photographer or an enthusiastic amateur, ask yourself the following questions.Do you only use flash in low light situations? Do you tend to leave everything to automatic mode when using flash, as you are unsure how to expose correctly for it? Do you feel you are not making the most of your (rather expensive) flash equipment? Do you just want someone to take you by the hand and show you how to confidently use flash, rather than have to plough through chapter upon chapter of theory in a book?By the end of this workshop you will be bursting to utilize flash creatively in your pictures, rather than thinking of it as a necessary evil for low light situations!

Transcript of Exposing with a flash!

Page 1: Exposing with a flash!
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Happy Bokeh Press

Saul McKeon

a how-to guide for mastering exposure when using off camera hot shoe flash

Exposing with a flash!

Photographer’s Workshop Series

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First published in 2012 in England by

Happy Bokeh Press

Copyright © 2012 Happy Bokeh Press

[email protected]

Happy Bokeh Press is an imprint of

Johnson McKeon LtdFifth FloorHorton HouseExchange FlagsLiverpoolL2 3PFEngland

www.johnsonmckeon.com

All titles in the Photographer’s Workshop Series are available directly from Happy Bokeh Press, as well as from all good retailers.

British Library Cataloguing in Publication Data.A catalogue record for this book is available from the British Library.

ISBN 978-1-909320-00-0 (print)

ISBN 978-1-909320-01-7 (e-book)

All rights reserved by the publisher.

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Welcome 1

How fl ash light affects exposure 3

How fl ash position affects exposure 13

How fl ash modifi ers affect exposure 19

And fi nally... 24

CONTENTS

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1Saul McKeon

Aim of this workshop

Today we are going to take the fi rst few strides of our ex-

ploration into fl ash photography. This journey begins by

mastering how to expose correctly for fl ash. Once we have

done that, we will take a quick look at how changing the

position of the fl ash unit affects the fi nal image. We will end

by looking at how fl ash modifi ers—such as snoots, grids and

gels—affect the exposure.

Once you are confi dent with setting and judging exposure

for a single fl ash unit, you are heartily encouraged to join

us in our follow-on workshops that fi rther explore the use of

fl ash lighting to enhance modelling, mood and atmosphere.

Welcome

Target audience

» Do you restrict fl ash to low light situations?

» Are you unsure how to expose properly for fl ash, so

tend to leave everything set to automatic?

» Do you feel you are not getting the most out of your

fl ash unit?

» Do you just want someone to take you by the hand and

show you how to use fl ash confi dently?

If you relate to any of the above, we suggest you read on!

Through the Photographer’s Workshop Series, we focus on

exploring how to master one aspect of photography at a

time, which:

» allows each guide to be concisely written and tightly

focused upon its particular topic, making it ideal for

busy people,

» enables enthusiasts to build up their knowledge and

skills at their own pace,

» caters for experienced photographers who can reach

straight for the guide they need to quickly fi ll a gap in

their skill set.

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Essential equipmentSLR Camera. We are using our trusty old Can-

on EOS 30D Digital SLR, fi tted with a Canon EFS

17-55mm f2.8 lens. You can pick up this kind of

quality kit second-hand for a small fraction of what

we paid for it a few years ago.

Camera tripod. You will need to keep the camera

in the same position relative to the subject while you

experiment with exposure. Anything sturdy will do.

We are using mid-range Manfrotto 055XPROB legs.

Off camera fl ash unit (ideally TTL-capable). We

are using a mid-range Canon Speedlite 430EX, con-

nected to the EOS 30D by a TTL fl ash cord. Once

you take the fl ash unit off the top of the camera,

you will need to mount it on something. The Canon

Speedlites come with a mini plastic foot for the fl ash

unit if you do not have access to a light stand.

Optional equipmentLight stand. We like the value for money lighting

accessories from Interfi t—though there are plenty of

others—and here we are using their COR751 stand.

Flash modifi ers. We play with Honl snoots, grids

and gels that quickly fasten to the fl ash head using a

velcro system. Great quality and portability in our

view—though again there are plenty of alternatives.

Remote shutter release. We use a Canon Timer

Remote Control (TC-80N3), because we have one

knocking around and it is easier than pressing the

button on the tripod-mounted camera. Any elec-

tronic remote shutter release (otherwise known as

cable release) will help you take sharp photos on

your tripod.

Prior knowledge

Before we begin, you should be comfortable with the basic

concepts of photography.

» You need to understand how to set the aperture and

shutter speed on your camera to produce the exposure

you want.

» You should also know how setting the aperture affects

‘depth of fi eld’.

If not, then no problem, fi rst ‘attend’ the workshop enti-

tled Now turn it off automatic! and then come back here

when you are ready.

Also, if you are unsure how to switch your fl ash unit’s me-

tering mode to manual (i.e. how to turn TTL off if you have

it) and how to zoom the fl ash head (if it can be zoomed),

you will need to refer to the manual for your fl ash unit.

Gear you will need

As the whole point of these workshops is to learn by do-

ing, you will need some basic photographic kit—see right

for what we used. Note that when we mention a particular

brand of equipment it is merely for reference, not because

we urge you to go out and buy the very same model! We

aim to keep kit lists to a minimum in our workshops, making

suggestions for other equipment you may fi nd helpful if you

can easily get hold of it; but no problem if you can’t.

Please bear in mind you do not need expensive equipment

to learn photography. By all means invest in decent kit on

which you can build—such as quality fl ash units and light

stands—but you do not need to use the latest top-of-the-

range camera; we certainly didn’t, so there!

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How fl ash light affects exposure

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Photo 3: f2.8 1/15s flash 1/8 powerPhoto 2: f2.8 1/15s no flashPhoto 1: f2.8 1/20s no flash

Hey... what happened there!?

The fl ash was positioned on the mini-

stand that came with it, around 1/4m

from the subject and to the camera’s left.

In keeping with this workshop, we had

switched the fl ash onto manual (i.e.

turned TTL off) and set the power our-

selves. We had also manually zoomed the

lens to 105mm. (See the next page if you

are not sure what all this means!)

The fl ash was clearly far too power-

ful even at just an eighth of full power.

Hmm?

Fortunately, this is where fl ash comes in.

So let’s attach a fl ash, switch it on and see

if we can enhance the light and shadow

on the subject.

Light and shadow work

together to make an object

look three dimensional—

which means shadow is as

important as light!key learning point!

Bumping up the exposure a mere 1/3 of

a notch brightens the picture—note how

we highlight in bold any change in expo-

sure settings from the previous photo.

However, this has resulted in a loss of

shadow detail in the petals.

A jug of fl owers on the kitchen table has

gracefully volunteered its modelling ser-

vices for this workshop.

Let us start by trying to get a good shot in

natural light—that is, without fl ash.

We begin by switching the camera to

manual mode, selecting a wide aperture

for a shallow depth of fi eld and setting

the shutter speed to that suggested by

the camera’s in-built meter. (If you do

not understand this, we recommend fi rst

looking at Now turn it off automatic! )

The resulting shot (above) is not bad—

though perhaps a bit dim?

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Photo 5: f8 1/15s flash 1/64 power

Photo 4: f2.8 1/15s flash 1/64 power

Zooming a fl ash

Some fl ash heads can be zoomed like a

camera’s zoom lens: focusing or spreading a

given amount of fl ash light. For this work-

shop we manually zoomed the fl ash head in

to its maximum—105mm for the 430EX—

which means the fl ash is at its most direc-

tional and intense.

Note the edges of a photo are likely to be

darker—vignetted—if an on camera fl ash

unit’s zoom setting exceeds the focal length

of the camera lens. This is because the fl ash

spreads out less than the lens ‘sees’.

Much better. But what has happened to the

background? Even if we like the dark back-

ground, it is our duty to fi nd out why it hap-

pened—especially given most indoor snaps of

people resemble this kind of shot!

When we turn the fl ash power down to its lowest

setting (see bottom right), we fi nd it is still too

powerful! So what can we do to prevent overex-

posure? Well we could move the fl ash unit fur-

ther away (see later), or we could zoom out the

fl ash head (see bottom left). However something

else we can do without touching the fl ash unit at

all is to narrow the camera aperture to let less of

the burst of fl ash light through the lens...

Flash power

Perhaps a bit misleading, as most fl ash units

can only fi re at a given fi xed intensity: where

its ‘power’ setting really refers to the dura-

tion of its fl ash. A fraction of 1/1 represents

the longest a given unit can sustain its burst

of fl ash and—in the case of the 430EX—

the shortest is limited to 1/64 of that period.

This means a given fl ash power setting

(e.g. 1/64) would put out more light on a

more powerful fl ash unit—such as a Can-

on 580EX or Nikon SB900—than on our

430EX: as power is relative to the unit itself.

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Photo 15: f5.6 1/250s auto-TTL flash

So, this time our fl ash exposure is simply a little ‘fi ll-in fl ash’ on the

candle (from camera right). Importantly, it is this understated fi ll-in

fl ash that has given us the artistic licence to reduce both the exposure

of the fl ame and the background without underexposing the candle.

Flash opens up the opportunity to be more creative—it gives us two exposures to play with!creative—it gives us two exposures to play with!

Somewhat paradoxically, fl ash allows

us to create darker photographs!

Now, while we could easily have experimented with getting the right

fl ash exposure by adjusting the fl ash power manually, here we let the

camera have a go by switching the fl ash unit to TTL mode. Not a

bad job EOS 30D, well done.

Note: if you don’t like the bright refl ection of the fl ash on the right of

the candle, fi nd time to join us in the workshop The studio look...

in a fl ash! where we explore the options for this sort of situation in

more detail.

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Photo 27: automatic exposure, with off camera TTL flash to subject’s left with -1 flash exposure compensation

Most modern cameras and TTL fl ash units have a ‘fl ash exposure compensation’ feature, allowing us to override the automatic TTL fl ash expo-

sure up or down a few notches. Here we dialled in some fl ash compensation on the camera, so that we didn’t have to play around with the fl ash

unit and risk losing the model’s attention.

By instructing the camera to reduce the fl ash exposure by one notch—the camera will narrow the aperture and/or reduce the fl ash power as it sees

fi t—we get a much softer effect. Check your camera and fl ash manuals to see if you have this feature—it is very handy at social events!

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natural light

fl ash light

And fi nally...At one end of the continuum are the photographers who insist upon

faithfully recording a scene using only natural light. At the other ex-

treme we have photographers who prefer to add their own interpreta-

tion to a photograph through extensive digital image post-processing.

Neither is the correct approach (and neither is wrong); it simply de-

pends upon what sort of photographer you want to be. The use of

fl ash in photography falls somewhere on this continuum. While some

photographers believe it is ‘dishonest’ to use ‘unnatural’ light, others

believe it lifts the craft from mere record-taking to that of an art form.

We fall into the latter camp. You decide where you stand for yourself.

We began this workshop by taking a photograph of a vase of fl owers

in natural light. We then proceeded to explain how fl ash can be used

to add depth, texture and interest to a subject. We explained how to

expose properly for fl ash, how to add depth and texture by moving the

fl ash unit, and how to use modifi ers to change the nature of the fl ash

light itself. So is fl ash photography right for you?

In the same way some artists strive for realism through a ‘chocolate

box’ approach to painting while others insist true art requires the art-

ist to add something of themselves to a scene, photographers also

have different attitudes toward their craft.

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