Archived posting to the Leica Users Group, 2006/03/21

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Subject: [Leica] Photoshop Like a Darkroom - Long Lesson
From: datamaster at northcoastphotos.com (Gary Todoroff)
Date: Tue Mar 21 14:55:32 2006

> Gary - any chance you can share cheat sheets - i know it's cheating
> but so long as the teacher doesn't see us .....
>
> ernie nitka
>
> photoshop challenged in Denver

OK, Scott and Ernie and whoever else is interested. Here is the
"cheat-sheet" I mentioned earlier for getting Photoshop (PS) to behave like
a darkroom regarding the concept of dodging and burning. The basic idea in
PS is that an "adjustment layer" (AL) lets through a PS effect (brightness,
contrast change, color saturation adjustment, etc) wherever the AL is white.
That same effect is blocked wherever the AL is black. An AL itself is ONLY
black and white and shades of gray. Creating the gray portions of an AL lets
a part of the effect into the appearance of the photo. That gray-softened
border in the AL is like the darkroom technique of moving your hands or
dodging tool continually to avoid an abrupt edge on the print where you have
modified the exposure.

There are a dozen different ways to do anything in PS. This technique keeps
file sizes smaller than duplicate layers of the Background and, once
learned, works rather quickly. The following instructions assume some
knowledge of PS already and won't make much sense to a beginner. Many local
classes are usually available for beginning PS, which is like showing you
where the brake, gas pedal and steering wheel are. You might get of the
driveway OK. But if you're comfortable out on the PS street, then let's hit
the freeway:

What follows is not casual reading, unless you like cookbooks. It's more of
a "lab" session, so you'll probably want to print out the directions for
reference as you do each part of the lesson while in PS.

1. Start Photoshop and open a digital photo file that could be improved by
what you would normally accomplish in the darkroom through some simple
dodging and burning. A good example might be a backlit face that is too
dark.

2. Use the Lasso tool to select an area that you want to brighten up. (Tools
palette, click and hold the Lasso box to get the three types of Lasso's to
display. Pick the one that has the angles on it, but not the angled one with
the little dots - it is probably the one already "remembered" by PS).

3. Make a rough outline with the lasso tool around the area you want to
dodge or burn. (Click, drag to the next spot, let go, click again and drag
again, eventually clicking back to where your started, thereby completing
the "polygon" around your dodge/burn area). Don't try to be exact around the
edges - just a general outline around and somewhat bigger than the area your
are dodging or burning. PS settings can be different on which way the Curve
graph is set up, so I can't tell you which direction to drag the graph
line - just experiment with raising or lowering the line within the graph.

4. "Feather" the image using the keystroke sequence: Alt-Ctl-D (It's on the
Select/Feather Menu, too). The number of pixels of feathering depends on the
size of your selection and the pixel dimensions of the overall photo. Try 50
to start. You will see all your sharp lasso angles get smoother. This
softens the edges of the Adj Layer you are going to make, meaning that the
AL boundaries go from white to gray to black instead of abruptly from white
to black.

5. Make a "Curves" adjustment layer. On the tools palette on the very bottom
middle, click the little half-moon, yin-yang symbol and Select "Curves". A
graph window appears. Click on the diagonal graph line and drag the line up
or down to darken or brighten your selected area of the photo. You can click
on a second point somewhere on the graph and drag it, too. For example,
making the typical "S" curve like you see in film graphs, you can increase
the overall contrast. Experiment. You are working on the AL at this point.
Although you see the effect on the photograph, you are not affecting the
original Background Layer. Don't worry yet about the selected boundaries on
your image going abruptly from light to dark as you change contrast on your
selected area. Click OK when the dodge/burn effect for most of your
selection looks right. If you get too many anchored dots on the curve,
simply delete them by clicking on a dot and drag it to outside of the graph.

(Sometimes, feathering the lasso selection is enough to give you already
what you want without needing to do the next adjustment layer step, but I
usually find that applying the Gradient tool to the adjustment layer removes
all traces of an otherwise obvious burn/dodge.)

6. Select the Gradient Tool on the tools palette. It looks like a step-wedge
tablet going from black to white. After you click it, make sure you should
also see the "step-wedge" selected at the top of the PS screen.

7. Click somewhere outside your selected area and drag across the edge of
your selection boundary (usually perpendicular to it) and a bit into the
selected area, where you want to feather the dodge/burn effect. In your AL,
this will "paint" a gradient from black to white, if the little black/white
squares are set correctly down at the bottom of the tool palette. If effect
is wrong, try reversing the black/white squares by clicking on the curved
arrow next to them. In your "Layers" palette, note there are two layers now
displayed. In the palette, the adjustment layer should be highlighted gray
(or blue?) as the "active" layer, and your Background layer will be white,
which indicates that it is NOT the active layer. If wrong, just click a
layer in the layers palette to make it the active one.

8. Try changing the Percent box at the top of the PS screen while your
Gradient tool is active. By lowering it, you create a gradient that goes
from gray to white, instead of black to white, giving a more subtle edge
effect.

The whole idea is got get a "fuzzy" mask (using your curves adjustment
layer) around your dodge/burn selection, the same as if you were moving your
cupped hands under the enlarging lens.

If the effect of your gradient is too much, it's easy in PS to back up a
step with the Edit /Undo menu or in the "History" palette. You can also
delete the whole AL in the Layer Palette and start over - the above steps do
not make any changes to your original Background layer.

If the whole gradient thing is not working right, then something is set
wrong at the top of the PS screen with your Gradient tool selected. It's a
bit too easy to get some odd settings up there and lose the simple tool
effect we're looking for. My setting across the top of the screen from left
to right in PS CS2 shows: The Gradient symbol as dropdown selection, the
regular checkerboard transparency pattern as dropdown, five types of
gradients as little buttons (does not seem to matter which has the square
around it), Mode: Multiply, Opacity: 100% (or some lower number for a more
gradual gradient), Reverse - unchecked, Dither - checked, Transparency -
checked.

Note again that all of this has not affected your original "Background"
photograph layer at all, so you still have the original photo to go back to
anytime and adjust it again or delete any adjustment layers and start all
over.

9. When I'm done or want to work on the file later, I always save it as a PS
format file. Click "Save As", give it a name (or leave the same name as your
original file, which was probably a .jpg or .tif extension) in the Save
window and click the dropdown to pick the file type selection at the top of
the list - Photoshop ".PSD". That keeps the file with both the original
Background and with the layers you have added. (If you want to save the file
at some future time as a .JPG file, you have to "flatten" the file - on the
layers palette, click the top right arrow and click Flatten Layers. Don't do
that though at this time.)

If you can follow this lesson by-the-numbers above, it will become second
nature with practice. Get the adjustment Curves layer dodge/burn approach
working for you using the basic concepts of Select, Feather and Gradient.
Then you can use the same technique for making other adjustment layer
effects.

Will be curious to hear if anyone actually tries this and if it made any
sense!

Best regards,
Gary Todoroff
(Tree LUGger)



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