Australian Camera — May-June 2017

DIGITAL DARK ROOM

70 71

STEP 1

Setting Up Auto

Bracketing

Select your camera’s auto

exposure bracketing (AEB)

function. This is commonly

assigned to either a ‘BKT’ or ‘

AEB’ button, but is also found

in the menus, either as a stand-

alone item or in the sub-menu

for drive modes.

Set the order or sequencing

to ‘Under>Metered Value>Over’

and choose a fi ve-frame sequence

with an exposure value (EV) of

one stop between each frame.

If your camera only allows you

to shoot three frames in an auto

bracketing sequence then do this

with a +/-2.0 EV adjustment for the

underexposed and overexposed

frames.

Set your drive mode to its high

speed setting and now, when you

press and hold the shutter, you’ll

take fi ve shots in quick succession.

The fi rst will be underexposed

by two stops to capture all the

highlight detail, the second will

be a little brighter, the third will

actually be at the regular exposure

settings, the fourth will be brighter

still, and the fi fth will be over

exposed by two stops to record

detail in the very darkest parts

of the frame.

STEP 2

Shoot The HDR

Sequence

Firstly, set the Image Quality to

RAW so you capture the image

fi le straight from the sensor with

no in-camera processing. Select

the aperture-priority auto exposure

mode (‘A’ or ‘Av’ on the dial or in

the info display).

Dial in the aperture you want,

such as f8.0, and focus on the

subject. Once you’ve achieved

focus, switch to manual focus

to lock in this focus distance.

This will prevent the autofocus

changing between the shots in

your sequence. It’s best to use

a tripod when shooting HDR

sequences to ensure the camera

doesn’t move, but because the

software will automatically align

the shots, you can also shoot

hand-held – just keep as still as

possible if you do. Now press the

shutter button and fi re off your fi ve-

shot burst. You’ll be able to review

the underexposed-to-overexposed

sequence of shots on screen.

STEP 3

Create A New RAW

Once you’ve copied your bracketed

images to your computer, select

them all by holding ‘Ctrl’ (or ‘Cmd’)

and clicking on them, then right-

click on one of the fi les and select

‘Open with>Adobe Photoshop CC’.

Because these are RAW fi les,

they’ll load into the ACR interface,

and the fi ve fi les will appear in the

Filmstrip on the left-hand side.

The fi rst fi le will be highlighted

so, to select them all, click on the

little four-bar icon next to where it

says “Filmstrip”, and click ‘Select

All’. Now click on the four-bar icon

again, and this time, select

‘Merge To HDR’.

When the ‘HDR Merge

Preview’ window appears, ensure

that ‘Align Images’ and ‘Auto Tone’

are ticked, and set ‘De-Ghost’ to

‘Medium’.

‘Show Overlay’ will reveal

areas where movement has been

detected between the shots in the

sequence, and ‘De-Ghost’ ensures

that only one image is visible. Now

click on ‘Merge’, and then save

the fi le.

STEP4

Assess The HDR RAW

The newly-created RAW fi le will

appear in the ACR interface. This

is made up from an exposure

blend of the fi ve source images,

and the only difference between

this and a regular RAW is that the

exposure slider has a much greater

latitude. It normally runs from -4

to +4 stops, but on the HDR fi le,

it extends a full ten stops in both

directions. The extremes won’t be

of any use, but you do have the full

exposure latitude of all fi ve fi les,

and the data is all contained in the

same image.

The ‘Auto Tone’ option selected

when merging the fi les usually

does a good job of producing a

natural-looking, balanced image,

but you can override any of the

settings using the sliders in the

control panels.

CamMayJune17_068-071 DigitalDarkroom.indd 70 13/04/2017 12:16 AM