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In this exercise I am going to introduce you to luminance blending inside of
Photoshop which allows you to either drop out luminance levels inside of the
active layer or force the display of luminance levels inside of the layers
behind the active layer. And we are going to see how this works using
a couple of other images. We are going to take a break from our composition
in hand from this almost blue image and we are going to take a look at these two
guys right here. Big cloud.jpg and Lightening.jpg. They are both found inside
of the 10_Advance_Blend folder and what we want to do is we want to take this
lightening as captured by a photographer who goes by the handle Subret
at istockphoto.com. We want to composite it against this image
here of the clouds from photographer Don Wilkie. Not only we do want the lightening
to look like it's coming from the clouds, but we want to intertwine the
lightening inside of this clouds as well. So we want to create a completely all
together credible composition here. So how do we go about masking lightening?
Well, once upon a time you know before chapter 09 when you mask that fantastic
hair image, you might have thought that lightening was a little bit daunting.
But now you know it's no big deal right. We can go ahead and switch over
to the Channels palette here as I will do and then we could find the high contrast
channel which in the case of this image is a Green channel.
We could go ahead and duplicate it by dragging it down to this little page icon
at the bottom of the Channels palette. We could rename it mask and then we
could bring up the Levels dialog box by pressing Ctrl+L or Command+L on the Mac
and then we would say, you know what, we want the lightening to be a lot
lighter, but we want the background to be way the heck darker, and there is our mask.
It's basically all it takes, right? Then we click OK and we would go ahead and
convert that mask into a selection by Ctrl or Command clicking on it, here
inside of the Channels palette. Then we will switch back to our RGB image.
Maybe copy the lightening by pressing Ctrl+C or Command+C on the Mac. Then we
will switch back to the clouds image and then we paste it by pressing Ctrl+V or
Command+V on the Mac like so. And that's actually darn easy to do, but the
problem is then we are going to have the blend it, because now we have all
this color fringing really kind of shadow fringing going on around the edges
or the lightening, and as it turns out this is the harder way to work. Even though
wasn't really all that difficult to mask the lightening. Now that
we know some of the fundamentals of masking. It still more work than we all of be doing,
because we can take care of this lightening in its entirety without any masking
whatsoever using luminance blending. So check it out. Let's go ahead
and undo the pasting of that lightening into the clouds image. Let's return
to the lightening image, press Ctrl+D or Command+D on the Mac to deselect
it. I want you to press Ctrl+A or Command+A on the Mac in order to select all
of the image and then press Ctrl+C or Command+C on the Mac in order to copy it.
So Ctrl+A, Ctrl+C on the PC. Command+A, Command+C on the Mac.
Let's return to the clouds and do a Ctrl +V or a Command+V on the Mac. Now these
images are pasting exactly in the place, because they are of the same size. The
lightening in the Big cloud image are of the same width and same height in
pixel so they have the same pixel dimension. Now I am going to switch back over to a Layers
palette. Let's go ahead and rename this layer lightening. All right, now
it's time to start blending these two images together. Step number one is to
drop out the dark stuff and keep the light stuff and if you want to keep the light
stuff in the image and you want to drop out the dark stuff, the most obvious
screen mode has got to be a lighten screen mode right. One of the screen
mode inside the lighting family and it's got to be stream. So we will press
Shift+Alt+S or Shift+Option+S on the Mac to apply the screen mode and you can
see how much work that one mode does by itself. Totally nondestructive, we
are not a single pixel inside of either the lightening or the cloud image so
we could always change your minds later, if we wanted to.
Next, we need to drop that more of the darks, because we have this overall
lightening effect from the lightening layer. We need to drop out more of the
darks and we are going to do that using luminance blending. To get to the
luminance blending options inside Photoshop, you double-click on the layer.
There are actually couple of different ways to do it by the way. You can either
double-click on the thumbnail in this case or on the empty area of the layer. I
want to double-click on the names, because that allows you to rename the layer
right, or you could go down to the fx icons and you could choose blending
options. So either of these work. Every single one of these techniques will
bring up the Blending Options panel of the gargantuan Layer Style dialog box here.
Down here at the bottom, these two slider bars represent the luminance blending
options inside of Photoshop. That's not what they are labeled, but that's what
they are. And the This Layer slider bar, I sound ridiculous when I say, the
This Layer slider bar, but that's what it is. The This Layer slider bar
controls which luminance levels are visible inside of the active layer, the
Underlying Layer slider bar which should really be called Underlying Layers,
plural, controls which luminance levels are visible inside of the composite
view of all of the layers below the active layer.
All right, so we are going to play with the This Layer slider first here.
Notice if I drag this white slider triangle right here, I am making light
pixels inside of the layer transparent. So I am saying anything that has a
luminance level of 123 or lighter, make it transparent, and anything that has a
luminance level of 0 for Black up to 123, go ahead and make that visible, go
ahead and keep it visible. Well, that's exactly the opposite of what
I want to do, right because now I am revealing the inside of the lightening bolts,
I am making them transparent, but I am leaving the exterior of the area outside
of the lightening visible. Well, I really want to get rid of that stuff. So
let's go ahead and make the lightening visible once again by dragging
this white slider all the way over to the right and let's make the background invisible
by dragging the Black slider over to the right. So in this case, I am saying that anything
that has a brightness value for 129 or darker, make then invisible on the active
layer. Anything that has a brightness value of 129 up to 255 which is
White, leave that visible subject of course to the Blend mode settings and the
Opacity settings as well. Now that ends up producing some very jagged transition.
If you zoom in on your layer, you will see that you have all kinds of jaggies
at work inside of the lightening bolts. So we need to soften the transitions by introducing
some fuzziness. Remember fuzziness from the Color Range dialog box.
Well, we have got fuzziness associated with the luminance blending options
as well. But getting to that fuzziness, involves a little bit of trick.
If you look very closely at this triangle, this black triangle right here,
on you screen. You probably can't make it out on the video. But there is a little
cleft in the middle. There is a little line right down the middle of the triangle,
and what that's telling you is it's really two triangles in one.
You can break these triangles apart and you do that by pressing and holding the
Alt key where the Option key on the Mac and dragging the triangle into two
pieces like so. And once you drag it apart, you can see that you are
introducing fuzziness to your image, to the active layer. So we no longer have
those jagged transitions. I am going to go ahead and move the first
half of the triangle here on the left side of the black triangle to 85. you don't
have new miracle control incidentally. You can't enter a number. But
you can, of course, track the numbers here inside of the dialog box, just
keep your eye on them. And I am going to move the right half of the black
triangle over to 175. So in this case, when I am saying is anything
that has a brightness value of 0 through 85, make that absolutely transparent.
Anything that has a brightness value of 175 up to 255, leave that opaque
subject to the Blend mode and the Opacity settings and then anything that has
a brightness value 85 to 175, ramp it up. So ramp from Transparency to Opacity, so that
we have a nice, soft transition inside of our image. Now I am going to go
ahead and click OK in order to accept that modification. Let's zoom out from the
image, so we can take in the entire thing, Shift+Tab away the palettes and you
can see this is what the lightening looks like now. This was before subject to
just the screen mode and nothing else and this is the lightening subject to
luminance blending here inside Photoshop.