Digital Photographer - UK (2020-05)

Be more creative with luminositymasksandcompositeimages

Advanced Photoshop

We’ve seen how Photoshop can be used to

make exposure adjustments, both globally

and selectively. It can also be used to make

colour and tonal adjustments, but to some

extent these techniques can similarly be

achieved in Lightroom and Capture One. So,

what can Photoshop do that can’t be done in

a RAW processor?

Until recently, luminosity masking was only

available in Photoshop, although now it is also

available in Capture One. The idea behind

luminosity masking is to create very accurate

masks using the values of the pixels, rather

than manually drawing a mask, which can be

time-consuming and inaccurate.

For example, instead of drawing a lasso

around an object, like a rock (which may or

may not be completely accurate), you can

uminosity

asking made

imple

1

Createthemask

UsingtheADP

LumiFlowpanel,choose

fromanumberof

differentwaystocreate

aluminositymaskinthe

topsection.Theresult

isshownimmediately

inPhotoshop,sokeepselectinganoption

untilanappropriate-lookingmaskarrives.

2

Addto

adjustmentlayer

TheADP LumiFlow

panellets youadd

theluminositymask

toanadjustment

layerbyclickinga

button– choosethe

adjustment youwant.

Here,acurvesadjustmentlayer wasadded.

3

Workthelayer

Adjust the

luminosity mask like

any other mask. Here

the top of the image

has been masked out

completely, so the

lightening of the exposure with the curve

adjustment will only affect the edges of the

clouds in the bottom of the frame.

Left

Clouds with excitement

The final image has lightened

the foreground clouds,

creating more interest and

life. However, the top of the

image remains unchanged

by manually adjusting the

luminosity mask

Above

Clouds needing a lift

The idea behind luminosity

masking is to select all the

tones of a similar value and

create a mask. With this

approach the mask can

be pixel-accurate. Here we

want to lighten the clouds

minosity masking is

fancy name for a very

actical technique

minosity masking can

achieved in Photoshop

anually, but there’s a lot

steps involved. Many

otographers instead

oose to use a specially

sking plugin, such as those

from Tony Kuyper and ADP LumiFlow. This makes

the process of creating the masks quick and easy.

create a luminosity mask based on the tonal

values of the object (how light or dark it is).

You can end up with a very accurate mask

around the object.

Of course, this approach isn’t always perfect

because other areas in the photo that are

of similar tonal values will also be selected,

or maybe the subject you are selecting

has a varied range of tonal values, so some

areas won’t be selected. It is quite usual to

manually adjust a luminosity mask to get the

precise outcome you want, but nevertheless,

luminosity masking is an incredibly powerful

tool because it is using the actual pixels in the

image itself to create the mask. Luminosity

masks can be very accurate.

So the key remaining preserve of Photoshop

is found in composites or ‘merging’ two

or more images together. For landscape

photographers, composites are commonly

used for replacing a sky, but they can also be

used for dropping in a tree, a rock, a person

or a building. We no longer need landscape

photographs to be literal, they can be

created first in your imagination and then in

Photoshop using layers.

Image layers can have masks applied to

them, just like adjustment layers. The mask

is drawn around the element to be dropped

in, so only that element and nothing else is

visible. To be effective, the mask needs to

be very precise. Of course, instead of using

masks, elements can be cut out and left on a

transparent background before being dropped

into place – there are many different ways to

achieve the same result in Photoshop.

AFTER BEFORE

TECHNIQUES