non-destructive editingcoursecontent.ntc.edu/.../photoshop_editing.pdf · 2012-08-28 ·...
TRANSCRIPT
Non-Destructive Editing This Photoshop tutorial describes how to retouch photographs
without ever touching the original. The same techniques can
be used for any graphic design, not just photographs.
The great advantage of non-destructive editing in Photoshop
is that you can easily adjust image effects or adjustments,
even weeks or months later. They also allow quick editing and
increased flexibility. Everyone who uses Photoshop should
know these techniques, because they really make Photoshop
so powerful.
This tutorial is split into several sections:
• 50% Gray Layer
• Adding Noise
• Sharpening
• Lighting Effect
• Layer Styles
• Adjustment Layers
• Clone and Patch Tool
• Masks
• Dodge and Burn
• Sponge Tool
• Other Techniques
1. 50% Gray Layer Look at a 50% Gray as a neutral color. Everything darker or lighter than 50% Gray will have an effect on
most blending modes (but not all). You'll understand this better throughout the course of this tutorial.
Let's have a look how we can fill a layer with 50% gray.
Add a new layer by clicking on the Create a New Layer icon in the Layers Palette. Fill this layer with
50% Gray by going to the menu and selecting Edit / Fill.
The following window will pop-up:
In the pull down menu marked with red we then select 50% Gray and click on OK.
There is a second way to fill this layer with 50% Gray;
Edit the foreground color...
... by clicking on the foreground color in the tools bar.
In the Color Picker window that opens you type 808080 in the area marked with red.
But wait, there's even a third way to add a 50% Gray layer. Add a new layer by holding down the Alt key
(Option key on the Mac) and clicking on the Create a New Layer icon .
A window will pop-up in which we can set the blending mode for example to Overlay and by selecting the
option Fill with Overlay-neutral color (50% gray):
In this example I've used the Overlay blending mode, but you can select any other blending mode in this
New Layer Window to create a neutral layer as long as that particular blending mode allows you to select a
neutral color that's either 50% Gray, Black or White and if it does, then the text at the bottom will change
accordingly. For example select Difference and the text at the bottom will change to 'Fill with Difference-
neutral color (50% Black)'.
In this Photoshop tutorial we're only going to focus on 50% Gray layers and for the following blending modes
50% Gray is considered neutral:
• Overlay
• Soft Light
• Hard Light
• Vivid Light
• Linear Light
• Pin Light
Be aware that some of these blending modes are not available in older versions of Photoshop.
2. Add noise In the following sections we're going to make use many times of the following image:
You can right click on it if you have Windows and then select Save target as... to save this file on your
hard drive. I don't know how to save the image on a Mac, but hopefully most Mac users won't have a
problem to figure that out on their own.
The first thing I'm going to show you is how to add noise to an image by using a separate layer.
Open the image and add a new layer by selecting the Create a new Layer icon in the layers palette.
Fill this layer with 50% Gray by selecting in the menu: Edit / Fill... and selecting 50% Gray:
Click OK.
Now go to the menu and select Filter / Noise / Add noise... and use the following settings:
The next step is to go to the layers palette and to change the blending mode to Soft Light:
The result:
We could also have picked Overlay as our blending mode which increases the contrast of the noise:
This is a good example of what non-destructive editing is all about; we're able to add noise without ever touching the original. If we need a different setting, then we just throw away Layer 1 which contains the
noise, create a new layer, fill it again with 50% Gray and use different settings for the noise filter. Now you
might wonder why it's not better to use undo. There are two reasons for that;
• Undo is not possible if you just opened this file (with the noise layer included), since the history is
not saved.
• Undo is not always possible, since Photoshop restricts the numbers of steps you can take back,
depending on your preferences and memory limitations.
You might wonder why it's not better to duplicate the original background layer and apply the noise to this
duplicate. Yes, that works, but quite often you have more than one Photoshop technique applied to an
image.
Let's say that you've added noise and applied 5 adjustments to a single layer. Throwing away that layer
would would mean that you're not only throwing away the noise but all 5 adjustments.
So you would have to start all over which is a lot of work and can easily lead to mistakes. I admit, if you're
lucky the noise was the last thing you added, but quite often this is not the case and again, like I said earlier,
you can't undo an adjustment for an image that was saved and closed before you had the desire to make
this adjustment.
One other advantage of this non-destructive approach in Photoshop is that we're able to make adjustments
to this noise layer only. In our example we might consider to apply an effect to the noise (slight blur for
example), use a different opacity for the noise layer or even change the blending mode to a different one for
which 50% Gray is considered neutral. We can even add a mask to the noise layer to remove the noise in
the sky:
Of course in this image it doesn't make sense to add noise to the face only (it's just an example), but it is
important to know that there will be occasions that we only want to add noise to one particular area and this
should remind you how to do this.
In this example we've added noise to a photograph, but of course we can add it to everything we like. This
technique is for example very useful if you want to design textures or want to make photographs look older
(in combination with other techniques).
3. Sharpen In this section I'm showing you a technique that is commonly called High Pass Sharpening.
It's another example that shows how to do things in a non-destructive way.
Again, open the original photograph.
We're now going to duplicate our background layer.
Click on its icon in the layers palette, hold down the mouse button and drag (A) the layer to the Create a new layer icon and release the mouse button. This will create a new active layer ( in front of it) called
Background copy:
Set the blending mode of this layer to Overlay.
This time go to the menu and select Filter / Other / High Pass... and select a radius of 0.5 pixels and click
OK.
We have now sharpened the Background layer using the Background copy layer and again this an
example of a non-destructive technique. Turn off/on the eye icon in front of the Background copy layer a few times to see the difference between
the original version and the sharpened version:
You're not limited to use the Overlay blending mode for this technique and you might try out these other 6
blending modes that I told you about earlier for which 50% Gray is considered neutral:
• Overlay
• Soft Light
• Hard Light
• Vivid Light
• Linear Light
• Pin Light
Btw, and this is slightly off-topic, the High Pass sharpening technique is a very popular technique to sharpen
images, since it does a good job of sharpening edges while avoiding sharpening too much noise/texture in
an image. 4. Lighting Effect In this section I'm showing you how to use Photoshop to add a non-destructive lighting effect to an image.
Open the photograph that we've used earlier and again, add a new layer and fill it with 50% Gray and set
the blending mode of this layer to overlay like we did with the 50% Gray layer in the previous section about
Sharpening. No screenshots this time, since you've already seen them earlier in this tutorial.
Go to the menu and select Filter / Render / Lighting Effects...
Use the following settings:
The result:
Of course you're not restricted to a single light or color and again neither should the blending mode or
opacity restrict you to apply additional effects to this lighting layer.
In the following example I've used 3 different colored lights to light a stone floor:
But hey, that's not all. We can even add a Lens Flare (Filter / Render / Lens Flare) to a 50% Gray layer
that we've set to blending mode Hard Light like in this example:
Again, we have avoided to damage the original image.
5. Layer Styles Layer styles were introduced to create editable effects. Most people think about shapes and text (like my
Car Name in Chrome Photoshop tutorial) when you mention layer styles, but the same layer styles can also
be applied to photographs.
You can add a layer style to an existing layer by clicking on the Add a layer style icon in the layers
palette.
Note: Layer Styles can only be added to layers that are not locked and this includes the background layer.
To unlock a background layer, double click on it in the layers palette.
Many of the effect that can be used are also part of what we call Adjustment Layers (more about them in
the next section).
The advantage of layer styles is however that we can apply more than one effect, without having the need to
create a separate Adjustment layer for each one of them.
Look at this example:
...achieved by adding the following effects to the layer style:
I'm not going into too much detail as what the different settings are, but instead it's important to understand
that adding a single layer style can change the looks of an image tremendously and every effect inside this
layer style is still editable.
Btw, if you're still interested in the settings then download the the original style here (right click, save target as...). Be aware that I've created this style in Photoshop CS for Windows, so compatibility issues may exist if
you use this style on a Mac or a different version of Photoshop.
You can load the style in Photoshop by clicking on the little black arrow in the Styles Palette (A) and then
selecting Load Styles... (B) in the menu that slides out:
In general you will use layer styles mostly to add effects to shapes and text, but it can also be useful for
photographs.
In this example I've added the Color Overlay and Gradient Overlay effects to create a sepia look:
But we can even take it a step further by adding a mask to this layer style by clicking on the Add Layer Mask icon :
...and like always, everything is editable, the layer style is editable, the mask is editable and the original is
not damaged in any way. 6. Adjustment layers
Adjustment layers are really powerful and while layer styles are mostly used for shapes and text,
adjustment layers on the other hand are often used to retouch photographs.
You can add an adjustment layer by clicking on the Create new fill or adjustment layer icon in the
layers palette.
Here's an example of the 15 layer adjustments that are available in Photoshop CS:
Let's have a look at some of them.
Solid color: this will create a layer with a solid color. You might ask yourself what this is useful for. This can
be useful if you want to colorize images in combination with the color blending mode for example or to color
shapes when used in combination with clipping layers as seen in this example:
The other advantage of a Solid Color adjustment layer is that the layer is always completely filled, regardless
whether you increase the canvas size of your image.
Btw, if you wonder what a clipping layer is; a clipping layer only affects the pixels of the layer to which it's
'clipped'. You can clip a layer (in our example the two fill layers) by activating the layer that you want to clip
(you'll see a in front of it) and pressing Ctrl+G (command + G on the Mac) or Ctrl + Alt + G (Command +
Option + G on the Mac) if you use Photoshop CS2.
Gradient: the gradient adjustment layer is not often used by most people, yet it can be very useful. It allows
you to add any kind of gradient that is normally available if you would have used the regular gradient tool in the tools bar and you can even create your own gradient. You can also select what kind of
gradient you want; linear, radial, angle, reflected or diamond gradient. You can adjust scale, reverse angle and what a lot of people don't know, even move the gradient around in the document window!
Pattern: a pattern adjustment layer can be useful if you want to add a pattern to an object or layer.
Levels, Curves, Color Balance, Brightness/Contrast, Hue & Saturation, Selective Color, Photo Filter and Channel Mixer are very often used by people who want to correct color and/or lightness in
photographs.
The others are Gradient Map (creative effects), Invert (Inverts an image, very useful in combination with
masks), Threshold (for example useful to find the black and white point in an image) and Posterize
(creative effects).
It's important to remember that a lot of these adjustments layers can be used in combination with a blending
mode and/or a mask or opacity. This makes them even more powerful and often saves you space in your
layers palette, because you need less layers when you plan to use masks in combination with layer
adjustments.
Non-Destructive Editing Page 1 / 2 / 3 7. Clone Stamp and Healing Brush Tool Let me start first by saying that these tools were first introduced in Photoshop 7.
The Clone Stamp and Healing Brush tools are best used on a separate layer.
Use the photograph that we used throughout this Photoshop tutorial and add a new layer on top by clicking
on the Create a new layer icon in the Layers Palette. Either select the Clone Stamp or the Healing Brush tool and look at the options bar; you'll notice an option called Use All Layers .
Make sure that this option is selected when you plan to use either the Clone Stamp or Healing Brush tool on
a separate layer.
Because we have selected Use All Layers, all changes will take place on the empty layer and not on the
original. If we make a mistake, then we can simple select the Eraser Tool in the tools bar, select a soft
or hard edged eraser with the right size and opacity in the options bar and slowly erase the corrections we
made.
The greatest advantage is of course that we can now easily correct our mistakes. It's also important to
mention that we can make other corrections to this separate layer, like applying a filter like Gaussian Blur to
soften the edges, but also adjust color and lightness, change opacity or even add a mask if we feel like it, all
things we wouldn't be able to do if the corrections were applied to the original image instead.
Also important to know is that you you're not limited to a single layer that contains the corrections of the
Healing Brush or Clone Stamp tool. You can have separate layers on top of the original, each one with a different purpose but all with one thing in common: Use All Layers selected.
Please remember; the source area that you use to clone or heal when you use several layers will always be
what's visible in your document window.
To give you an example; let's say that we want to remove the blemish in this part of the photograph:
We add a new layer, grab the clone stamp or healing brush tool with Use All Layers selected and remove
the blemish:
If we now add another layer on top of Layer 1 and use the area that has the blemish removed (marked with
the red circle in the last image) as the source area for the tool we use, then the tool will only use the source data that's visible. No blemish is visible because layer 1 placed new pixels on top of this blemish, so the
source that will be used are the pixels on layer 1. Of course, if we select an area outside this red circle as our source, then the tool will use the pixels of the Background layer.
I know, it's a mouth full, but I hope you understand it, otherwise experiment with more than 1 layer to
understand the whole concept a bit better. 8. Masks Layer Masks are a very powerful part of Photoshop and that is for a couple of reasons:
• Layer Masks are editable selections that play an important role in non destructive editing
• Layer Masks offer flexibility because they can be almost completely treated as a full gray scale
image, which allows the use of filters, selection tools, adjustment tools, etc.
• They have a visual strength, meaning that with a short look on the layers you can see how they
affect the image
• They offer extra flexibility by being part of vector masks, layer sets, adjustment layers, etc.
• Layer masks allow you to save selections
It's important to look at my Layer Masks Photoshop tutorial to understand and truly appreciate the power of
masks and what role they can play in non-destructive editing. Again, I want to remind you that all layers,
layer styles, vector masks, layer sets (or groups as they are called since PC CS2) and adjustment layers
can have a mask attached. 9. Dodge and Burn
With the Dodge and Burn tools it's the same story as with the Clone Stamp and Healing Brush tool;
they're best used on a separate layer.
For that we're going to need another 50% Gray layer. Again, open the image that we've used so many times and again add a 50% Gray layer and this time set the blending mode to Soft Light. Make sure that the 50%
Gray layer is active ( a in front of it).
Now select either the Dodge or Burn tool and select a small soft brush and start working on some highlights
and/or shadows. Again, changes will only take place on the 50% Gray layer so the original stays intact.
In this example I've used a combination of doge and burn to work on a few strands of hair:
There's one shortcoming about this technique and that is that the Range option in the option bar...
...will have no effect. The range option normally tells the Dodge or Burn tool which pixels to affect most.
Since we're working on a 50% Gray layer, we always have the same average light value and there are no
shadows and highlights (both part of the range options), only a single midtone.
I don't consider that a major limitation, because now have the chance to go back to correct your mistakes
and most corrections done with the dodge and/or burn tool will be minor anyway.
We can correct dodge and burn mistakes by using Undo (Ctrl + Z or Command + Z on the Mac), Step Backward (Alt + Control + Z or Option + Command + Z on the Mac), the history palette or by painting
back the areas on the 50% Gray layer that we've darkened or brightened with the original color using a
brush and a foreground color with a value of #808080 (which is 50% gray as we've seen in section #1
about 50% Gray layers).
If we still want to be able to use dodge and burn using the range option, then we need a different approach.
Let's say that the area that we want to adjust is mainly inside the selection shown in this example:
Open the photograph and make a rough selection of the face with any of the selection tools as shown in the
above example. I've used the Elliptical Marquee tool to make it easier on myself, but in reality I would
have taken more time for this selection by using for example the Lasso Tool and/or creating a mask. So
consider to make it easy on yourself too, after all it doesn't change anything about the basic principle that I'm
going to discuss here.
We're going to make this a soft selection to avoid that any adjustments close to the actual selection will end
in a very abrupt way like in this example:
We turn the selection into a soft selection by going to the menu and selecting Select / Feather... We now have to enter a Feather Radius:
The number depends on the resolution of the image and since our photograph is rather small, I've selected also a rather small value of 20 and probably a value of 10 will be fine too (experiment)
The next step is to copy the area with the soft selection to a new layer. We do that by right clicking (control
on the Mac) on the layer's name in the layers platte (in our case it's named Background) and selecting the
option Layer via Copy in the context menu...
...and the result is this:
Now you can use burn and dodge on this layer with all the advantages of the range option without touching
the original.
Instead of dodge and burn you can of course for example also use levels or curves adjustment layers in
combination with a mask, but that again doesn't give you the range options that the regular dodge and burn
tools allow, but like I said earlier, I've never considered that a real limitation. The truth of the matter is that
dodge and burn are generally only used to make minor adjustments so the first technique in this section that
used a 50% Gray layer will be in most cases sufficient. 10. Sponge Tool The Sponge Tool is used in Photoshop to change the saturation of one particular area in an image. It's
the same story as with the dodge and burn tool and that is that it's mostly used for a few minor corrections
for small areas. For that purpose the last solution that was shown in the previous section about dodge and
burn will work just fine. Instead of using this tool it's of course possible to make use of an adjustment layer
like for example a Hue & Saturation adjustement layer in combination with a mask. 11. Other Techniques Non-destructive editing doesn't stop here. Other techniques that can be used for example are duplicate
layers that are blended with the original image using a specific blending mode or opacity. A good example is
for example the soft focus effect...
...which is nothing more than a duplicate of the original layer set to 50% opacity, blurred with filter / blur / gaussian blur... and a radius of 3 pixels (use a wider radius to increase the effect)..
But you can also use a soft blue brush on a separate layer set to overlay to add some eye shadow:
Final comments Non-destructive editing is a very important aspect of
Photoshop. I hope that my tutorial makes it clear how powerful
all these techniques can be used not only to achieve results
fatser, but also to be able to make single adjustments as many
times as possible without interfering with other adjustments at
the same time. The more you gett he hang of these
techniques, the more you will see the quality of your work
improve.