Layers in Photoshop

The Layers Palette in Photoshop is like the skeleton upon which other parts of the image are attached. It is the first serious palette that the beginner comes to, usually followed by the Channels Palette and eventually the Paths palette. These three palettes are grouped together in the default palette nesting.

A layer in Photoshop and the pixels upon it are a separate part of an image and may be moved, copied, colour adjusted and turned on or off independently from the other parts of the image. When a Photoshop file is saved all layers are saved as part of that file even if they are turned off in the visibility box. Only layers, which have the visibility eye showing, will show in a print of the image. Fundamental properties

1. A simple file has only a Background Layer (i.e. one directly from a camera or scanner), which may be changed to a regular layer by double clicking it in the layers palette whereupon it becomes Layer 0 by default. Layers may be c double clicked in the layers Palette and given their own name, of your choosing.

2. Layers can be moved independently of other layers and the rest of the image.

3. Layers higher up in the layer stack in the palette show above the content of other layers in the image.

4. A layer may be physically larger than the image in which it sits. The pixels outside the bounds of the host image are called "big data". Moving a layer containing big data reveals that data and big data are saved with a Photoshop file. Big data are lost when a file is trimmed. Cropped or flattened.

5. In the default Windows colour scheme the active layer is coloured blue in the layer stack unless it is being dragged when it changes to yellow. Only active layers or layers linked to the active layer may be moved or changed.

6. A layer may be dragged and dropped onto another image and in doing so it "lands" where you let go of the left mouse button,. If you hold down the Shift key as you drag and drop the moved layer lands right in the middle of the host image.

Essential shortcuts

1. The Tab key hides all palettes

2. F7 toggles the Layer Palette on and off.

3. Typing a numeral sets the active palette to that numeric value of transparency e.g. typing 5 sets the transparency at 50%.Typing two digits e.g. 55 sets it to say 55% transparency.

4. Ctrl-clicking a Layer in the Layer stack loads the pixels in that layer as a selection.

5. With a selection active, hitting Ctrl-J copies the selected pixels and pastes a copy of them into a new layer above the active layer.This is called "floating" a selection. The pixels in the original layer are left unchanged.

6. Holding the Alt key down and clicking the horizontal line between an Adjustment Layer and the Layer below it groups the Adjustment Layer to the regular layer and then only effects that one layer in the stack. Without grouping an Adjustment layer affects all layers below it in the stack.

Layers Other Layers

There are a host of other "layer" names and features. The main ones are

1. Adjustment Layers - these adjust the colour of the layer with which they are associated or all the way down the layer stack below. By default that are made with a layer mask.

2. Type Layers - these hold type in editable form. The name in the Layers Palette takes the actual text.

3. Vector Layer - these hold vector shapes and are created by default when you draw using the vector shape tool from the Tool Bar.

Layer Sets Layers

Regular Layers may be organised into colour-coded sets for large, complex projects. A Layer Set may be expanded to show all its constituent layers or collapsed to show as just a single entity, thus taking less space in the layer stack of the layers Palette.

LAYERS IN ACTION

Tom Lee set up the image of Leanne toffing it up as the Lady of Tabley Hall [1].The brown fire screen was a bit dull and uninteresting and one light was out [2]. An existing, illuminated bulb was cloned onto a new layer then moved across into position. To add a touch of mystery the entire image was then copied and pasted to a new layer, then scaled and distorted to fit into the fire screen of the original. To allow the structure of the fire screen fabric to show through the opacity was decreased to 90%.This process was then repeated twice more with ever smaller repeat images and gradually declining opacity. The final image is shown on the left [4].

Note that each layer has been accurately named. While it is unlikely with so few layers, more complex projects need good naming management and layer set-making to keep tabs on what is what!

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Photo Quote: Photography, alone of the arts, seems perfected to serve the desire humans have for a moment - this very moment - to stay. - Sam Abell