We often use S-Curves to enhance
contrast. This is actually just fine if we don’t have any problem
with darkened/blocked shadows or aggressive highlights. But often you
want to improve the contrast without damaging the shadows and highlights.
Note: For many images the differences may be subtle
but still strong enough to make improvements to your images. Best you
try these techniques
yourself. To show the differences we use the symbol
to indicate that a mouse over will show the previous or original image
(move the mouse cursor slowly in and out of the image).
We would like to add some midtone contrast to the above image. A
good tool to use is PS Shadow/Highlight.
We set all values to zero except the midtone slider.
workflow we actually perform this operation on a layer. (We
describe in our ebooks how to make use of a layer based workflow).
This way we can even make the contrast to strong and adjust the strength
via the opacity of that layer.
While this is a good solution it lacks the flexibility we want because
Shadow/Highlight cannot be used as an adjustment layer. That is
why we use a curve adjustment layer that comes close to mimic the midtone
contrast in Shadow/Highlight.
Midtone Contrast Curve
We lock the curve in the shadows and the highlights to protect
these important areas of our image.
Midtone Contrast Curves Layer
There is one general problem with using S-Curves to enhance
contrast. At the same time we add contrast we also shift
the colors and
this may be welcome or even not. By setting the Blending
mode of this
layer to Luminosity we avoid this shift.
Layer set to Luminosity
set to Luminosity
Often the truth is that you may like some of the color shift
but not all of it. This is not to difficult to achieve. We
duplicate the curves
layer and set the copy to Blending Mode “Color”.
Now you can control the color shift by setting the right
in our example).
Controlling Color via opacity
Final tweaked image
If you use this technique we would advise
you to sharpen first as you then can tweak the contrast and colors
the two layers any time later:
• Variations of the midtone contrast curve itself