Section 5: Retouching Tools

The Photoshop retouching tools works on the principal of taking information from existing pixels and altering them to create a particular effect. It is important to remember that the retouching tools employ destructive editing. This means that the original pixels are being ‘destroyed’ and replaced by ‘new’ pixels. To enable the easy roll back of changes to our image, Photoshop has a few very useful features: History Palette, History Brush and Snapshot.

• Retouching Primer
• History Palette, History Brush and Snapshots
• Clone Stamp, Healing and Patch tools
• Blur, Sharpen, Smudge
• Dodge, Burn, Sponge
• Colour retouching
• Quiz

Retouching Primer

The retouching tools works on the principal of taking information from existing pixels and altering them to create a particular effect. It is important to remember that the retouching tools employ destructive editing. This means that the original pixels are being ‘destroyed’ and replaced by ‘new’ pixels. To enable the easy roll back of changes to our image, Photoshop has a few very useful features: History Palette, History Brush and Snapshot.

History Palette

The History Palette stores all recent actions and lets us undo one or more actions with a simple mouse click. To use the History palette simply click on the editing state you want to rollback to. The number of available roll back states depends on the amount specified in Photoshop’s preferences. This number will depend on the amount of memory on your system.

History Brush

The History brush has the same basic function as the History Palette but enables us to paint back only portions of an image to a previous state. To use the History Brush, we first have to set the source state to which the brush will return the image. To do this click the square to the left of the history state you want to return to.

A small History Brush icon will appear in the square. It is also possible to set a snapshot as a source state.

 

Snapshots

By creating a snapshot, we are creating a reference point in our image that we can return to at a later time. This is useful when trying out different effects on an image. When we open an image, a snapshot is automatically created for us and can be seen at the top of the History Palette. To create a new snapshot, click on the snapshot icon at the bottom of the History Palette.

Example: Apply a layer style to a layer and create a snapshot. Use the History Palette to return to a state before the layer style was applied. Now apply a different layer style and create another snapshot. By simply clicking on the snapshots it is possible to see what two different styles will look like without having to reapply them.

The snapshots of an image will not be saved with the image. Once the image is closed, the snapshots will be lost.

 

Clone Stamp, Healing and Patch tools

These three tools are probably the most useful and most used tools for anyone working on photographic images. No matter how hard we try, taking the perfect picture, where no retouching is necessary is difficult, even for professionals. These three tools enable us to easily repair an image by removing spots and blemishes.

    Clone Stamp (aka Rubber Stamp)

The Clone tool takes a sample of pixels from one area of an image and applies it to another area. To use it we first take a sample by pressing Alt / Option clicking on a portion of an image. Then move the tool to where the sample must be reapplied and click again.

The size and shape of the sampled area is changed by choosing different brushes. This can be done directly from the options bar when the Clone Tool is selected.

The Aligned checkbox, when unchecked, takes the sample from the original spot over and over until a new sample area is defined. When checked the sample area is automatically moved in relation to the Clone tool.

Exercise 5.1

In this exercise we will add a couple of extra bullets on the table using the Clone tool.

1. Open image S5E1.jpg from the CD.
2. Select the Clone tool from the Toolbox and set a brush size of 65px with a hardness of 0%.
3. Move the tool tip over one of the bullets and press Alt / Option while clicking to select the source area.
4. Move the tool to where you want to clone the new bullet to and click again.
5. Because of the patterned surface, be careful not to clone too much around the bullet. This will cause the surface around the new bullet not to match.

Changing the Blending mode of the Clone tool changes the look of the cloned pixels depending on the underlying pixels.

The opacity and fill options are similar to those found in the layers palette we discussed earlier. In the case of the Cone tool changing the opacity will affect the cloned pixels and the blending of the pixels (if a blending mode is selected). The Fill option will affect only the cloned pixels but not the blending of those pixels.

Healing and Spot Healing Brush

Similar to the Clone Tool, the Healing brush samples pixels from the image and applies it elsewhere on the image. The Healing brush, however, also matches the lighting, transparency, shading and texture to the pixels being healed. The result is a seamless blend of the new pixels into the rest of the image.   

The Spot Healing brush is similar to the Healing brush, but does not need sample pixels to work from. It automatically samples pixels from around the retouched area.

Exercise 5.2

In this exercise we will do some spot retouching on a portrait.

1. Open image S5E2.jpg from the CD.
2. Select the Spot Healing bush from the Toolbox.
3. Set the brush size in the Options bar to 10px and make sure Proximity Match is selected.
4. Click on the white and brown spots to create an even skin tone.

Patch Tool

The Patch tool is also similar to the Healing brush, but instead of using a brush to define the sampled area, the Patch tool uses a selection.

Exercise 5.3

In this exercise we will remove the date stamp from an image.

1. Open image S5E3.jpg from the CD.
2. Select the Patch tool from the Toolbox. Make sure the Source radio button is selected.
3. With the Patch tool, draw a freehand selection around the orange date stamp in the bottom right corner.
4. Click inside the selection and drag it to the left until the date stamp disappears.
5. For another approach, select the original snapshot in the History palette to revert the image back to its original state.
6. In the Options bar, select the Destination radio button.
7. Using the Patch tool select a section of the beach and drag over the date stamp. The orange numbers are now replaced with the selection we made.

Play around with this to get a proper feel for how the Clone tool works.

 

Blur, Sharpen, Smudge

These tools are mostly used to perform quick tasks. As their names suggest Blur and Sharpen tools will blur and sharpen edges. Especially the Sharpen tool has a much more precise and powerful alternative, the Unsharp Mask filter (more on this in the filter section. These tools are useful though if you want to blur or sharpen only a portion of the image without first making a selection and applying a filter. The Smudge tool will smear pixels, similar to dragging a finger through wet paint. It is more of a painting effect tool than a retouching tool, but can be useful when used in conjunction with the Blend mode option.

 

Dodge, Burn, Sponge

These tools are mostly used to perform quick alterations brightness, contrast and saturation to only a portion of the image.

The sponge tool will, depending on the setting in the options bar, increase or decrease the saturation of pixels in a particular area. When in grayscale mode the Sponge tool will either increase or decrease contrast in a certain area.

Dodging and burning are traditional photographic terms. It means to lighten or darken an area of an image. The function of the Dodge and Burn tools are exactly the same. Unlike in the darkroom we can specify whether the dodge/bur tools affect the highlights, midtones or shadows of an image. As with the sharpen tool, there are more effective ways to lighten or darken an image with a much better overall result.

 

Colour retouching

The topic of colour and colour management in Photoshop and other software packages are so complex that many books have been written on the subject. We will be scratching the surface by taking a look at colour retouching. To get the best quality retouched image, it is advisable to start with the best quality image possible.

Before we start lets look at the way different colour interact with each other. We will use a colour wheel as a reference for this.

Colour Wheel

The colour wheel shows all the primary and secondary colours and their relationship to each other.  As we can see each colour has an opposite, also known as a complimentary colour. This means that to remove a certain colour cast from an image, we need to add more of the opposite colour.

Example: To remove a green cast, add more magenta.

It is also possible to increase or decrease a certain colour by adjusting the two colours on either side.

Example: To change yellow, increase/decrease both the red and green.

This may sound simple, but it takes a well trained eye to do complex colour retouching. We will stick to the basics though.

Variations

Variations is an intuitive way to colour correct an image. To open the variations dialog click Edit>Adjustments>Variations. The thumbnails in the window that follows gives us a preview of what our image will look like when we add or subtract a particular colour. These changes can be applied selectively to the shadow, midtone or highlight areas. When selecting the saturation checkbox, the image is either saturated or desaturated. The fine/coarse slider enables us to make either subtle or more drastic changes.

 

Exercise 5.4

In this exercise we will try to adjust the colour balance of the image to a neutral tone.

1. Open image S5E5.jpg from the CD.
2. Open the Variations dialog.
3. Because the image has a lot of white areas, we will use this as our reference. Of all the thumbnails, ‘More Cyan’ brings us closest to a neutral image.
4. At the top of the dialog we can see a comparison of the image we started with and the current image.
5. Make any further adjustments as needed and click OK.

Colour balance

The Colour Balance tool is a more precise way to correct a colour cast in an image. It works on the same principle as Variations, but it is possible to specify new values to each of the colour channels.

As we saw in the colour wheel opposite colours are on the same slider axis. Moving the slider towards Cyan actually reduces the amount of Red in the image, causing the colour cast to change. Like the Variations tool we can specify whether to work on the shadow, midtone or highlight areas.

Hue/saturation

The Variations and Colour Balance commands are both very good tools to remove colour casts from images, but changes are confined to a certain tonal range (shadows, midtones and highlights). The Hue/Saturation tool enables us to make global changes that affect the whole tonal range of an image.  

From the dropdown menu it is possible to select which colours will be affected by any changes we make. If the ‘Master’ is selected the changes will affect all the colours in the image.

Checking the colorize checkbox will tint the image. The tint can then be fine tuned by using the hue/saturation/lightness sliders.

 

Levels

The levels command changes the tonal range of an image. When it is opened a histogram of the image is displayed. The histogram graphically represents the shadow, highlight and midtone (gamma) of an image. We can use the sliders underneath the histogram to adjust the shadow, highlight and midtones of an image. By dragging the highlight slider to the left, the current highlights in the image are brightened. By sliding the shadow slider to the right, the shadows are darkened. We can also adjust the midtones of an image by adjusting the slider in the centre. Unless a dramatic effect is needed, an ideal histogram extends across the full width of the graph. This indicates an image with a full tonal range.

 

Exercise 5.5

In this exercise we will adjust the tonal range of an image using some of the tools we have looked at.

1. Open image S5E5.jpg from the CD.
2. Open the Levels dialog with shortcut Ctrl+L / Cmd+L and move the highlight slider to the left until the clouds are well exposed. Click OK. Do not worry what the mountain looks like for now.
3. Create a snapshot of the image by clicking the snapshot icon or selecting ‘New Snapshot’ from the History palette menu.
4. Open the Levels dialog again Ctrl+L / Cmd+L and adjust the midtone slider to bring out some of the detail in the trees. Do not overdo it otherwise the trees will look washed out. Do not worry about the effect on the sky. Click OK.
5. Go to the History palette and click the box to the left of the snapshot you made in step 3. This sets the source state that the History brush reverts back to. In this case it is a well exposed sky.
6. Select the History brush from the Toolbox and adjust its size to about 400px with a hardness of 0%. Use the History brush to revert the sky back to snapshot state.
7. Compare the end result with the original image by clicking on the first snapshot.

Section 5 Quiz

1. What tool will we use to remove spots from an image?
2. What is Magenta’s complimentary colour?
3. What is another name for Gamma?