Photoshop Layers
An Introduction to Photoshop layers
Before we begin discussing Photoshop layers let me remind you that this is a work in progress page and as such there are no images at the moment ..they will be added soon. I will not go into any heavy detail here, that can all be had in the Photoshop help, what we need to have is an understanding of the relevant terms for use in a real life photo restoration project.
So what are Photoshop layers and how can they help us when restoring or enhancing a photograph ?
First lets “ clear up “ this concept of opacity. Opacity is a fancy way of describing transparency designed to confuse beginners !!. If something is 100 % opaque then it is in effect 0 % transparent and if some thing is 100 % transparent then it is 0 % opaque.
Fill levels ..As well as opacity, which affects the blending modes (described below) applied to the layer, you can set a fill opacity for layers. Fill opacity affects a layer without affecting the opacity of any layer effects that have been applied to the layer. So fill effects basically are concerned with the actual image on a layer and not with the blending modes. Initially I would leave this alone until we get into the finer details of photo restoration.
At there simplest we can think of layers as stacks of transparent sheets, we are looking down from the top and how far down the stack we can see depends on the transparency of each layer. If the top layer is 100 % opaque i.e. not transparent then all we see is this layer, those below are hidden. If the top layer is 0 % Opaque and the layer below that is 100 % opaque (0 % transparent) all we see is the second layer, the top layer is invisible and the second layer hides all the layers below that. I am sure you can then see that we can adjust the transparencies of different layers to allow more or less of the underlying layers to show through.
The first layer which is automatically created with an image is the background layer, it cannot have any layers beneath it and it is best left as is. It can, if needed be converted to a normal layer simply by changing it’s name. You can then add more layers and move them beneath this layer.
Layers are independent of each other ( unless you specifically link them) and as such each can be manipulated independently allowing for a mind boggling set of permutations. You can link the positions of layers so that as you move them they move in unison.
You can hide layers using the eyeball icon to the left of a layer, this is very good for quickly seeing the effect a layer has. Layers can be grouped and one layer can be set to influence a whole group of child layers. More importantly for us layers can be set as adjustment layers, we will discuss them in detail later on but basically instead of say doing an overall contrast adjustment to a photograph you would typical make a contrast adjustment layer, in this way the contrast adjustment can be fine tuned and manipulated with respect to other layers. This allows for precision adjustment to the image which are easily removable.
Blending Modes
OK so we can use multiple layers on an image with varying ratios of transparency and as adjustment layers we can use them to change the image in some way, maybe contrast, maybe blur. But there is another very powerful aspect of layers that we can use and this is the blending mode option.
Blending modes describe how a layer interacts with the layers below it, how it’s effects are “blended” into the overall image.
The are a large number of blending modes available, some are not really used that often and some are almost considered to be standard modes used very often. The problem is when explaining the modes that they are very esoteric and in all honesty the best way to see what they do is to try them !! Some of the standard modes, like Darken, Lighten and Overlay are fairly straight forward, others are far more arcane. Rather than just regurgitate the list and descriptions I urge you to read the manual on this one. But be prepared.. the descriptions are very dull !! ( But the manual does show some useful images of the modes in action.
Later I hope to show some real image examples of the effects of the various blending modes and when we get into a real life example of photo restoration I will show you what are the best modes to use for a particular scenario.
In the next section I will give a brief run down on masks and in particular layer masks as we will need to have a basic understanding of what they are and how to use them later
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