Layers Part 4

ADJUSTMENT LAYERS

Adjustment layers can be very, very important! As you probably know Photoshop has advanced filters that can artificially change the brightness, contrast, sharpness and levels of a picture. Although these options are of the highest quality when they are applied to a picture they permanently change that picture. For example, changing the contrast of a picture tends to wash out some of the finer tones. This is no problem provided that you do not want to change the contrast back down again. What happens if you've spent hours on a picture only to realise that the contrast was too high after all! If you now wanted to turn the contrast back down a bit you will loose the fine tones that used to exist. As a result and the quality of the picture will be much less than it could have been!

The solution to this problem is to add an Adjustment Layer. An Adjustment Layer will apply a correction (such as a contrast change or levels etc.,) to all layers below it. Because it does not permanently change those layers below it you can alter the picture correction at any time you like. Make no mistake using Adjustment Layers can save you hours of work if something goes wrong!

So how do we use the Adjustment Layers? They are added pretty much the same way as any layer. To add an Adjustment Layer just click on the add Adjustment Layer Icon (encircled in red below).

Up will pop all the adjustment options you can alter as can be seen below:

I've chosen the Brightness/Contrast Layer... option which on a very high setting changed

This: to this:

Below is what the final layers palette looks like with the adjustment layer added.

The background layer has the original picture and the top layer is a rather weird looking adjustment layer. Notice that the Adjustment Layer is split into two parts with a link icon in-between them. The left section is the actual adjustment icon. If you double-click on this icon it will allow you to change the adjustment settings (i.e. turning the contrast up and down etc). On the right is a masking effect. Every Adjustment Layer comes with a mask effect as default. Masking effects are used in a similar way to layers but will be dealt with in another article since it will complicate the situation. For now just accept that a mask effect is added with and adjustment layer and having it will allow you to rub out parts of the Adjustment layer so that the picture underneath shows through.

CLIPPING EFFECTS

Okay this is not really a vital thing to learn but I'm adding it to make this article more complete. A normal layer can be converted into a clipping layer. What this means is it will act as a stencil so that the layer above it will only appear in the shape of the stencil below. Basically this is used to create those effects were you want one picture below to show through the one above it. I know that's about as clear as mud to you, so let me show you what I mean.

Start a new picture with a white background. Then open up the zebra picture found in your Photoshop samples folder, or any picture you like, and paste that picture over the top of the white background.

Then add a new blank layer to use as a clipping layer. The final layer setup should look like this:

The zebra is at the top, the background is at the bottom and the layer we are going to use as a clipping layer is in the middle. Now, go in-between the zebra layer and layer 1 and hold down the Alt key on your keyboard. The mouse pointer should turn into a pair of overlapping circles as can be seen in the above picture. Once the mouse pointer changes left-click with the mouse and you will get the following setup:

Notice that the zebra layer has been moved to the right and has a downward arrow on it. This means that the zebra picture will only appear over what is painted in the clipping layer. Try painting on the clipping layer (layer 1) and you will see what I mean. You should get an effect something like this:

That's it for the layers guide. You should now understand almost everything about using layers. As time goes on you will just learn how best to use them by instinct. The next step after layers is to understand masking because they are similar subjects. Masking is almost the same as layers but allows you to create special kinds of masking effects that can have gradients. Understanding Selections, Layers and Paths is half the fight with Photoshop, once that is mastered the rest should follow quite quickly.