What are adjustment layers?
Photshop’s adjustment layer offer a way to apply visual changes and adjustments to your photo such as Curves, Levels, Hue and Saturation and a lot more. These are adjustments in a non-destructive way which means that it’s reversible.
An adjustment layer can be altered or deleted at any time, unlike the direct application of an adjustment to an image layer.
The end result of applying an adjustment layer is exactly the same as applying an adjustment directly to the image, it’s just that it’s much easier to update or delete whenever needed.
The only downside of using adjustment layers is that if you want the layers within the file to remain editable after you have saved the file you are required to save the file as a PSD (Photoshop Document).
This file will contain all your Adjustment Layer information and settings and while this is incredibly handy it does lead some huge file sizes.
A PSD file is a working file format, it is the format behind the scenes rather than the one that should be on display.
How do I create and adjustment layer?
There are two ways to apply an Adjustment Layer to your image.
The first is through the top file menu; Layer > New Adjustment Layer then you will see the list of adjustments available to be applied to the image.
Alternatively skip down to the layers pallet and along the bottom of the palate you’ll see a circle icon that is half black and half white. This is the “Create New Fill or Adjustment Layer” option. Click this and it will reveal all of the different adjustment layers that are available.
Once you’ve selected the adjustment you want, for example Levels, the usual dialogue window for that adjustment will appear enabling you to make the adjustments in the usual adjustments way.
Once you’ve finished with the adjustment just click OK and you’ll see the adjustment appear as a new Layer in the Adjustment Layers Pallet.
Adjustment layers will appear alongside image and graphics in the layers pallet and can be re-edited at any time or popped into a group as with any other layer.
To fine tune any adjustment made in an Adjustment Layer simply double-click the Adjustment Layer, Layer and it will reopen once again showing you the usual adjustment dialog window.