- [Instructor] Now I'll introduce you
to my favorite colorization function of all,
which is called gradient map.
And while that may sound like an odd name,
it's actually very accurate.
Because what it does, is it allows you to map a gradient
across the luminance levels inside of an image.
So, whereas this image contains essentially one color,
which is that sepia,
this image contains a total of three colors.
That is to say reds inside the shadows,
cyans across the midtones and blues across the highlights.
And so I'm going to go ahead and switch over
to my custom black and white portrait.
And I'll turn on the brightness contrast layer
just to finish off the effect,
and I'll go ahead and select that layer as well.
And then what you want to do,
is go up to the window menu
and choose the adjustments command
to bring up the adjustments panel.
Now notice this very last icon right here
allows you to create a gradient map.
Go ahead and press the Alt key
or the Option key on the Mac and click on it
in order to force the display of the new layer dialogue box.
I'll go ahead and call this layer infusion and click Ok.
Now, so far we haven't done much of anything
and that's because we're mapping
this black to white gradient across a black and white image.
And so we're mapping the shadows to black
over here on the left,
and the highlights to white over on the right.
And so notice if I turn this layer off,
it brightens just a little bit.
And then when I turn it back on,
I increased the contrast.
And that's because of the Gaussian distribution
associated with this gradient.
Another word starting on the left-hand side,
it brightened slowly,
then it travels through the mid-tones more quickly,
and then right here at the end in the highlights,
it slows down as well.
And so that necessarily produces a higher contrast effect.
But while that may be interesting,
that's not of much use to us,
what we want is to infuse some color into the image.
In which case, click on this down pointing arrow head
to reveal a menu of folders.
Your folders may look different by the way,
but I'm going to twirl open blues right here,
and I'm going to select this guy Blue 27
which is going to give us this kind of murky blue effect.
However, bear in mind
that you can change the blend mode if you like.
So currently the blend mode is set to normal as by default.
But notice if I switch it to color,
then I'm going to bring back the original luminance levels.
So in other words,
I'm going to restore my highlights as well as my shadows.
Whereas if I go with normal,
things are looking a lot more murky.
Here's another example.
I'll click on that down pointing arrow head once again
and I'll twirl open reds this time around
and select the very first gradient from that folder.
Now, in this case, the colors are mapped backwards.
And so, as I was saying,
just as when you're working with a levels adjustment layer,
the shadows appear on the left-hand side of the histogram
and the highlights appear on the right-hand side,
that works with the gradient as well.
So in this case, we're mapping the shadows to white
and the highlights to black
which of course is not what we want.
Go ahead and turn on the reverse checkbox
and you'll achieve this effect right here.
If you want to create your own custom gradient,
then turn that reverse checkbox off,
go ahead and switch from reds back to basics,
specifically this guy, black white,
and that's just because that's a good starting point.
And now I'll twirl that guy closed,
click off the menu to hide it.
And this time I'll click on the gradient ramp
in order to bring up the gradient editor dialog box.
And now I'll click right about there
to add a new color stop below the ramp, by the way.
Notice my location value is 50%
which happens to be exactly what I want.
And so now to change the color,
you can double click on the color stop
or just click once on this color swatch right here.
And now I'll dial in the hue value of 210 degrees,
I'll set the saturation, let's say to 50%
and I'll set the brightness value to 50% as well
and then I'll click OK.
And you can see that I have now infused the midtones
with this darkest shade of blue.
If you also want to infuse the shadows, let's say,
then you would double click on the first color stop.
And this time around,
I'm going to go with a huge value of 270 degrees for violet,
I'll leave the saturation value set to 100%
and I'll crank the brightness value up to 33%
at which point I'll click OK
in order to accept that change.
Now, let's say you want to save that gradient.
You do that in a kind of strange way.
The first thing you do, is name the gradient.
So I'm going to call it map to blue, let's say,
and then you click on a new button.
So you've got to name it before you click new
and then you'll see that gradient at the end of your list.
At which point, I'll click OK to accept that change
and I'll go ahead and hide my properties panel as well.
Now, as I was saying,
you can adjust the blend mode if you like.
So if I were to switch from normal to color,
I would bring back the more natural highlights and shadows
as we're seeing right here
or you can try out a different mode.
For example, we could increase the contrast
using overlay or back things off a little bit
with softlight.
And so I'm going to go with softlight like so,
and then I'll press the escape key.
So the blend mode is no longer active here on the PC,
and then we'll tap the 5 key
in order to reduce the opacity value to 50%.
And just to give you a sense
for what we've been able to achieve,
this is the colorless gray scale version of the image
and this is our subtle degree of colorization.
Thanks to the addition of a gradient map adjustment layer
here inside Photoshop.