Articles

Photoshop Layers 101

By John Tunney

Photoshop and Photoshop Elements both have a very powerful tool called Layers.   The classic analogy is to think of layers as sheets of acetate.  The bottom layer is your image.  Everything you do to the image – level adjustment, brightness/contrast, cloning, etc. – you do on a new layer or sheet of acetate placed over the original image.  Using layers in this way, you can work on individual aspects of your image without affecting all the other aspects. 

For example, if you want to adjust the contrast of the image, you create a contrast layer.  If you have a picture of a desert island with buried treasure and you want to add an X to mark the spot, then you create a new layer and draw an X.  You could make changes to your original layer, but then all the changes would be permanent. That’s the ingenious thing about layers: you can make changes to the changes and you can always go back to your original unaltered image.

There are several different kinds of layers, but I find it easier to think of them as falling into two basic groups: Image Layers or Adjustment Layers.  An image layer is just what it sounds like: a layer with an image in it.  This includes any layer with a picture, text or brushstroke that appears in the image.  Adjustment Layers control the tones and colors of an image -- things like brightness, contrast, shadow and highlight levels, hue and saturation – without altering the graphic elements of the picture.

Working with Layers

When you open an image you will see a thumbnail of it on the right hand side of your screen in the Layers Palette.  The image appears in a layer called Background Layer.  You create new and duplicate layers either by clicking on the icon in the Layers Palette or by using the drop down Layer menu at the top of your screen.

After opening an image, I usually start with the Adjustment Layers (Layer>New Adjustment Layer).  The three adjustment layers I work with most often are Levels, Brightness/Contrast and Hue/Saturation.  There are other adjustment options, such as Color Balance, Curves and Photo Filters.  However, I find I can usually get what I want by sticking with Levels, Brightness/Contrast and Hue/Saturation. Experiment and figure out what works for you.

As I said earlier, you can make changes to your changes.  For example, let’s say you create an Adjustment Layer for brightness /contrast.  You adjust brightness and contrast to where you like them and then you create a new layer to work on hue/saturation.  If after adjusting hue and saturation you decide you want to go back and change the contrast – no problem.  Click on the Brightness/Contrast layer and make the change

If after working with the Adjustment Layers you want to make some graphic alterations to the image, click on the Background Layer and create a duplicate layer (Layer>Duplicate Layer).  All alterations to the image – cloning, cutting, painting, etc. – are done on the duplicate layer.  This way, if you mess up or change your mind, you can go back to your original Background Layer.  I usually create a new duplicate layer for each action.  For example, if I have a picture of a flower and I want to clone some petals, I’ll create a duplicate layer first, name it “Petals” and then clone the petals.  If I then want to draw a smiley face on the image, I will create a new layer, name it Smiley Face and then draw the face on that layer.

The order of layers is important

In general, layers affect all of the layers beneath them.  For example, if you add an Adjustment Layer for Brightness/Contrast, it will only change the brightness and contrast of all the layers beneath it.  However, when you create a new Adjustment Layer, there will be an option to “Group with previous layer.”  If you click this option, it will limit the affect of the layer to the layer immediately below it.

You can also limit the affect of an Adjustment Layer to a selected area of an image.  To do this, use the Lasso or Magic Wand tool to select your target area.  Then when you create a new Adjustment Area, the affect will be limited to the selected area.

A new image layer will cover an image layer below it.  If you erase part of the image in the top layer, images from the layers below will be seen through the area that has been erased.

You can change the order of layers.  Right click on the layer you want to move and then drag it up or down into position.

Some other things to consider and remember:

- If you are going to use an art filter, distortion filter or any other tool that changes the graphics within an image, create a duplicate layer first and then make the change on the new layer.

- Turn off a layer by clicking on the eye icon in the left column of the layers palette.

- Delete a layer by dragging it into the trash bin in the layers palette.

Once you have the basics down there are lots of advanced techniques to try. The best way to learn is to experiment.  Just start playing and see what happens.

###