Exposing with a flash! by P J

Photographerâ&#x20AC;&#x2122;s Workshop Series

Exposing with a flash!

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

Saul McKeon

Happy Bokeh Press

First published in 2012 in England by Happy Bokeh Press Copyright ÂŠ 2012 Happy Bokeh Press www.happybokehpress.com info@happybokehpress.com Happy Bokeh Press is an imprint of

Johnson McKeon Ltd Fifth Floor Horton House Exchange Flags Liverpool L2 3PF England www.johnsonmckeon.com All titles in the Photographerâ&#x20AC;&#x2122;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.

C O NTE NTS Welcome

How flash light affects exposure

How flash position affects exposure

How flash modiﬁers affect exposure

And ﬁnally...

Welcome Target audience »

Do you restrict ﬂash to low light situations?

Are you unsure how to expose properly for ﬂash, so tend to leave everything set to automatic?

Do you feel you are not getting the most out of your ﬂash unit?

Do you just want someone to take you by the hand and show you how to use ﬂash conﬁdently?

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

Through the Photographer’s Workshop Series, we focus on

Aim of this workshop

exploring how to master one aspect of photography at a time, which:

Today we are going to take the ﬁrst few strides of our exploration into ﬂash photography. This journey begins by

allows each guide to be concisely written and tightly

mastering how to expose correctly for ﬂash. Once we have

focused upon its particular topic, making it ideal for

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

busy people,

position of the flash unit affects the final image. We will end by looking at how flash modifiers—such as snoots, grids and

enables enthusiasts to build up their knowledge and

gels—affect the exposure.

skills at their own pace, Once you are conﬁdent with setting and judging exposure »

caters for experienced photographers who can reach

for a single ﬂash unit, you are heartily encouraged to join

straight for the guide they need to quickly ﬁll a gap in

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

their skill set.

ﬂash lighting to enhance modelling, mood and atmosphere.

Saul McKeon

Prior knowledge Before we begin, you should be comfortable with the basic

Essential equipment

concepts of photography.

SLR Camera. We are using our trusty old Canon EOS 30D Digital SLR, ﬁtted with a Canon EFS

You need to understand how to set the aperture and

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

shutter speed on your camera to produce the exposure

quality kit second-hand for a small fraction of what

you want.

we paid for it a few years ago. Camera tripod. You will need to keep the camera

You should also know how setting the aperture affects

in the same position relative to the subject while you

‘depth of ﬁeld’.

experiment with exposure. Anything sturdy will do. We are using mid-range Manfrotto 055XPROB legs.

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

Off camera ﬂash unit (ideally TTL-capable). We

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

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

when you are ready.

nected to the EOS 30D by a TTL ﬂash cord. Once you take the ﬂash unit off the top of the camera,

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

you will need to mount it on something. The Canon

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

Speedlites come with a mini plastic foot for the ﬂash

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

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

you will need to refer to the manual for your ﬂash unit.

Gear you will need

Optional equipment Light stand. We like the value for money lighting accessories from Interﬁt—though there are plenty of

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

others—and here we are using their COR751 stand.

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

Flash modiﬁers. We play with Honl snoots, grids

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

and gels that quickly fasten to the ﬂash head using a

brand of equipment it is merely for reference, not because

velcro system. Great quality and portability in our

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

view—though again there are plenty of alternatives.

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

Remote shutter release. We use a Canon Timer

suggestions for other equipment you may ﬁnd helpful if you

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

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

knocking around and it is easier than pressing the button on the tripod-mounted camera. Any elec-

Please bear in mind you do not need expensive equipment

tronic remote shutter release (otherwise known as

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

cable release) will help you take sharp photos on

which you can build—such as quality ﬂash units and light

your tripod.

stands—but you do not need to use the latest top-of-therange camera; we certainly didn’t, so there!

How flash light affects exposure 3

Photo 1: f2.8

1/20s

no flash

Photo 2: f2.8

1/15s

no flash

1/15s

flash 1/8 power

A jug of ﬂowers on the kitchen table has

Bumping up the exposure a mere 1/3 of

gracefully volunteered its modelling ser-

a notch brightens the picture—note how

vices for this workshop.

we highlight in bold any change in expo-

The ﬂash was positioned on the mini-

sure settings from the previous photo.

stand that came with it, around 1/4m

natural light—that is, without ﬂash.

However, this has resulted in a loss of shadow detail in the petals.

We begin by switching the camera to manual mode, selecting a wide aperture for a shallow depth of ﬁeld and setting the shutter speed to that suggested by the camera’s in-built meter. (If you do not understand this, we recommend ﬁrst looking at Now turn it off automatic! )

Hey... what happened there!?

from the subject and to the camera’s left.

Let us start by trying to get a good shot in

adow work Light and sh ct make an obje together to mensional— look three di shadow is as which means light! important as Fortunately, this is where ﬂash comes in.

The resulting shot (above) is not bad—

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

though perhaps a bit dim?

if we can enhance the light and shadow on the subject.

Photo 3: f2.8

In keeping with this workshop, we had switched the ﬂash onto manual (i.e. turned TTL off) and set the power ourselves. We had also manually zoomed the lens to 105mm. (See the next page if you

are not sure what all this means!) key learning point! The ﬂash was clearly far too powerful even at just an eighth of full power. Hmm?

Photo 4: f2.8

1/15s

flash 1/64 power

When we turn the flash power down to its lowest setting (see bottom right), we find it is still too powerful! So what can we do to prevent overexposure? Well we could move the flash unit further away (see later), or we could zoom out the flash head (see bottom left). However something else we can do without touching the flash unit at all is to narrow the camera aperture to let less of the burst of flash light through the lens... Photo 5: f8 1/15s flash 1/64 power

Much better. But what has happened to the background? Even if we like the dark background, it is our duty to ﬁnd out why it happened—especially given most indoor snaps of people resemble this kind of shot!

Zooming a flash

Flash power

Some ﬂash heads can be zoomed like a

Perhaps a bit misleading, as most ﬂash units

camera’s zoom lens: focusing or spreading a

can only ﬁre at a given ﬁxed intensity: where

given amount of ﬂash light. For this work-

its ‘power’ setting really refers to the dura-

shop we manually zoomed the ﬂash head in

tion of its ﬂash. A fraction of 1/1 represents

to its maximum—105mm for the 430EX—

the longest a given unit can sustain its burst

which means the ﬂash is at its most direc-

of ﬂash and—in the case of the 430EX—

tional and intense.

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

Note the edges of a photo are likely to be

This means a given ﬂash power setting

darker—vignetted—if an on camera ﬂash

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

unit’s zoom setting exceeds the focal length

more powerful ﬂash unit—such as a Can-

of the camera lens. This is because the ﬂash

on 580EX or Nikon SB900—than on our

spreads out less than the lens ‘sees’.

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

Photo 15: f5.6

1/250s

auto-TTL flash

So, this time our flash exposure is simply a little ‘fill-in flash’ on the

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

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

ﬂash exposure by adjusting the ﬂash power manually, here we let the

ﬂash that has given us the artistic licence to reduce both the exposure

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

of the ﬂame and the background without underexposing the candle.

bad job EOS 30D, well done.

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

ally, ﬂash allows Somewhat paradoxic photographs! us to create darker

Note: if you don’t like the bright reflection of the flash on the right of the candle, find time to join us in the workshop The studio look... in a flash! where we explore the options for this sort of situation in more detail.

Photo 27:

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

Most modern cameras and TTL flash units have a ‘flash exposure compensation’ feature, allowing us to override the automatic TTL flash exposure up or down a few notches. Here we dialled in some flash compensation on the camera, so that we didn’t have to play around with the flash unit and risk losing the model’s attention. By instructing the camera to reduce the flash exposure by one notch—the camera will narrow the aperture and/or reduce the flash power as it sees fit—we get a much softer effect. Check your camera and flash manuals to see if you have this feature—it is very handy at social events!

And ﬁnally... We began this workshop by taking a photograph of a vase of ﬂowers

At one end of the continuum are the photographers who insist upon

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

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

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

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

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

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

flash unit, and how to use modifiers to change the nature of the flash light itself. So is flash photography right for you?

Neither is the correct approach (and neither is wrong); it simply depends upon what sort of photographer you want to be. The use of

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

ﬂash in photography falls somewhere on this continuum. While some

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

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

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

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

have different attitudes toward their craft.

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

natural light

ﬂash light 24