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I am still looking at the High- contrast elephant.jpg image. In the previous
exercise we learned how and why the Levels command, despite its amazing immense
power tool is no match for this elephant right here. And what you do? When the
Levels command fails, you move one step forward to the Curves command.
I'll show you what I mean. I'll go ahead and cancel all of here. Despite any
modifications I may have made, I may get to this point, so that's looking
better I guess, but not better enough, so I'll just cancel out, because you
don't want to heap one color modification on top of another if you can avoid it.
Levels and Curves really overlap each other, so really no sense in applying
Levels and then applying Curves right afterward. So I'll cancel out of here.
I'm going to go to the Image menu, choose Adjustments and there it is. Levels
command. Failure where this image is concerned, so we move just one step there
to Curves. So also notice that our keyboard shortcuts move one step. Ctrl+L or
Command+L on the Mac, for Levels, Ctrl+ M or Command+M on the Mac for Curves.
And that brings up this big whopping Curves dialog box right here, to give you
sense of what's going on. Even if you come to terms with Levels, and you are
trying to feel comfortable with it, then seem the Curves command is enough to panic
many people. But it's actually fairly straightforward once you come to terms
with it. So hopefully we will, over the course of these next few exercises.
Notice that right dead center in the middle of this ginormous Curves dialog box
here is this Luminance graph. And then inside of the graph, cutting across it
is this diagonal line, which is the Luminance curve. Now
I know that it doesn't make a lot of sense that I'm calling it a diagonal line
or Curve, when it's most certainly not a curve, but it wants to be a curve, and
it will be a curve, the second you start modifying it.
Also notice here inside of this Luminance graph that we have a Histogram. The
exact same Histogram we were seeing just a moment ago. Now that may puzzle you
a little bit, because it looks like it's squished, and it truly it's not
squished, it's stretched, it's what's going on here.
It is still 256 pixels wide, just as it was inside the Levels dialog box. It's
just that, because the Luminance graph is a square, the Histogram is scaled, so
that it's taller. All the bars in this Histogram graph here have been scaled
relative to the height of the graph as it were.
So anyway, we know by looking at this graph here, this Histogram, that we have
a lot of shadows over here on the left hand side, so just this huge peak of shadows.
Not too many mid tones, relatively few, and then quite a few highlights
dropping suddenly right there at the end. And these are the guys we need to fix.
We need to draw these highlights down to make them darker, and we
need to boost these shadows up to make them brighter. Then sort of, monkey around
with the midtones until we get rid of the color cast.
So how do we do such a thing? Well, here's how you work inside of this graph.
First of all make sure that you've seen the graph the way I am. This is default
RGB behavior by the way, where black is located over here on the left side of
the graph and white is located over here on the right side of the graph. And
that's the way I prefer to work, and that's the way that it works inside the
Levels command. So it's easier to keep things similar I figure, and also that's
the way I'm going to be working. So I just want to make
sure you are too, you probably are. But just to make sure, come down here to
this option that says Show Amount of, and if can't see it, by the way you got
this double arrow icon, you can go in and click on it to expand the Curve
Display Options. Make sure Show amount of is set to Light, 0-255, which are the
luminance levels, of course, as opposed to pigment, which will flip the graph,
notice that. Now blacks are over here on the right side, and whites are over on
the left side, and that's just confusing as heck to me anyway.
But that's the way it is by default for CMYK images incidentally. But you can
always switch it to light instead, if you want to. You can always work that way,
regardless of whether you are working on RGB images or CMYK image, or what
have you. Also notice this output graph right here, or output access is where
it actually is. It's going from black to bottom, to white at the top. Okay, so,
what does all this mean, how in the world do you work inside this crazy environment?
Well, what I suggest you do for this image, anyway, just for starters, just to get a sense
of what's going on is just go ahead and click right in the center of that
diagonal line, and notice I have done two things. I set a point, and I actually
moved it slightly, so I have curved what was formerly a straight diagonal line,
so it is now a curve. Ever so slight, it is not a super curve, just
a very, sort of a subtle curve at this point. But I can make it less subtle
by dragging it. So this becomes a custom point in my graph. I can put as many
points on this line as I like, as many as I can stuff into this graph at any
rate. Typically you work with maybe 4 or 5 points, you don't work with a ton. But
you can, you do have that level of control if you need it. Now, in my case I
have only got 3 points. I have got this point in the center, and notice by the
way it's an input level of 128. So thing started here, I'll put it back where
it was, where we've studied originally. Input of 128 and an output of 128, what that
mean is we are starting with a gray. So we are not working with Gamma anymore,
forget the whole Gamma thing. We are working with this Gray point, which
is 128, so it's right there in the center, between 0 for black and 255 for white. And
it's mapping to 128, so in other words, it's not moving at this point. But if I were
to drag it up, I'm going to boost the midtones inside of this elephant as you can
see, because I'm now saying, I moved my input level a little bit, because
when you move that point back and forth, notice that it changes that input value
right there, but that's insignificant at this point.
But now it's 124 so it's still right there somewhere near the center, and I've
moved it up to 153 so I'm elevating those neutral gray values right there.
Well, I'm leaving the black point alone, and I'm leaving the white point alone.
So this is just as if I modified the Gamma value inside the Levels dialog box.
I know I told you just a moment ago to forget about it. What I meant was forget about how
gamma is measured as an exponent, but this is the
same thing. This is just like taking a Gamma value that Gray slider bar
and moving it over to left in order to boost the midtones inside the image. And
this is the level of control you are afforded by Levels.
Now I can also either just grab this black point right there and move it
around, or notice here, I can actually drag this black point slider if I want
to, so that's analogous to the black point slider inside the Levels dialog box.
And I can move the white point slider if I wanted to do as well. But both of these guys
are going to increase the contrast of said pachyderm here,
and that's not what we want. So I'm going to go ahead and change this back
to 0, and change this one back to 255. Instead, what I probably want to do is
add more points for the quarter tones, that is, for these regions here inside
of the shadows, and well inside of the shadows and the highlights.
So for example, I can set a point here arbitrarily, I'm just clicking, and then
I could drag it down to sync those highlights a little. Now the images aren't
looking really great at this point. I'm just trying to give you a sense of
where we might go with it, and then I can click inside the shadows and I can boost those
guys up, and then if I wanted more control, I can click like right about here,
and take that down a little bit, and take these midtones down. You see, I can
just click and drag any points along this curve in order to modify the
luminance levels of the animal here in the background or the image, more
appropriately I think. And notice that as I do, if I drag a point
up where it is going to brighten that region of color, and if I drag it down
it's going to darken it, so that's something to bear in mind as well. And I could
drag upward so that I can bring out those shadows, and you can see now there's
like this rock, or this hideous grotesque form back here in the shadows that we
can draw out, we don't necessarily want to draw a lot of attention to it. But
we can if we want to, by modifying the points on the curve, on this luminous
curve, here inside of the Curves dialog box. Now that just gives you a vague sense of what's
going on. Notice by the way we have the show clipping, right there; we got
a Show clipping checkbox, that will show you where the clipping is occurring,
for either the black point or the white point. And you could also turn Show
clipping off, and you could Alt+drag if you want to the white point
or the black point. So you got those same controls, and that's an option
drag of course, of either those slider triangles on the Mackintosh side of
things. So a lot of overlap with those Levels controls as well. But just a
bunch more control inside of Curves. In the next exercise I'm going to basically
sling a bunch of keyboard tricks at you. Just rat-a-tat, and then you have them in
your brain some place floating around. And then we'll
use them, and actually make a better elephant in the near future. Join me,
won't you?