Lessons: Photoshop Basics

[Triskdaemon]

Like I said in the lessons thread, this is going to be a thread that will gradually work it's way through all of the filters, tools, and aspects of Photoshop. Photoshop is a very valuable tool for any artist, and the key to knowing Photoshop is knowing the uses and potentials of the tools it offers. One of the basic parts of Photoshop that people don't use to its full potential is the Layers Palette.

Layers

The layers palette looks like this:


The layering system in Photoshop is very simple - one on top of the other, and the bottom layers are by default obscured by those on top.

Buttons

Look at the buttons on bottom. From left to right, we have the Layer Styles button (Which is a whole different post... Don't worry about that one yet.), the Layer Mask button, the Set button, the Fill/Adjustment layer button, New Layer, and Delete Layer.
The last two are pretty self explanatory.
Fill/Adjustment layers change the attributes of the layers below them. For example, if you put an "Invert" layer (hold on the button for the menu of options) above other layers on your image, the layers below your new F/A layer will appear inverted, whereas the ones above will retain their normal coloring. This can be a powerful tool; if you have many layers and want to apply the same effect to a portion of them, you can put a F/A layer above them. There are many options for this type of layer, and I'll get into those in more detail some other time.
The Set button creates a Folder in the layers palette, so that you can organize your layers into a heirarchy. I almost never use it, but it can be nice when working with a LOT of layers.
The layer mask button creates a mask attached to your layer, a seperate image that governs the transparency of the main image on the layer. If you want the layer to be transparent or translucent at a certain spot, you simply paint the desired area black (for complete transparency) or grey (for a translucent effect). The darkness of the color influences the transparency.
Layer Styles, as I said, is much too useful to relegate it to a part of this post. I'll cover those later. Layer styles apply special effects to a layer, and are very, very powerful and useful.

Blending Modes

Blending modes are another important aspect of the layering system. They are, basically, the way that the top layers interact with the layers below them. These are also affected by the opacity slider on the top right of the menu. On the image above, the Blend mode menu reads "Normal." This is the default, where colored areas are opaque and transparency means see-through. When you move the opacity slider, the image fades away to nothingness. Simple enough, right? Now, let's review the uses of the other modes.
Dissolve: When you move the opacity slider, the image goes away pixel by pixel, with the remaining pixels staying at full opacity.
Darken: Simple enough - the darkest parts of the two layers show through. Any white areas covering black areas on the lower layer will become, in effect, transparent.
Multiply: Similar to Darken, but less of a strong effect.
Color Burn: Similar to Darken, but preserves coloring better.
Linear Burn: Similar to Color Burn, but a stronger, sharper effect.
Lighten: You guessed it! The opposite of Darken; light colors show through while dark colors are shoved aside.
Screen: Similar to Lighten, but smoother and less strong.
Color Dodge: Opposite of Color Burn.
Linear Dodge: Opposite of Linear Burn.
Overlay: Puts the color of the top area onto the bottom with respect to the luminosity of the bottom layer - lighter areas recieve more of the color.
Soft Light: Like Overlay, but, well, softer...
Hard Light: Puts the color on the bottom layer with little regard for luminosity.
Vivid Light: Transfers the color in a very strong way, makes it bright and sharp.
Linear Light: Similar to Hard Light, a bit sharper.
Pin Light: Puts the color down on the darker areas of the bottom image, leaving the light ones alone.
Difference: Inverts portions of the top image that are above lighter parts of the bottom image.
Exclusion: Like difference, but leaves the middle-luminosity range of the bottom image alone.
Hue: Transfers color in the parts of the bottom image that have the greatest amounts of color.
Saturation: Transfers the texture, not the color, of the top image onto the most colorful parts of the bottom image.
Color: Blends the colors of the two layers.
Luminosity: Projects the light and dark from the top to the bottom, leaving the color out.

Whew... sweatdrop

A couple more things - you see those buttons that are labeled "Lock:"? Those are really useful. The checkerboard one on the left is the Transparency lock. It prevents you from drawing on the transparent sections of the image, useful for preserving outlines.
The brush, the pixel lock, prevents changes to the layer.
The position lock prevents layer movement.
The last button locks all three.

Now, how do you use this information? Make pictures! Play around with the blend modes, with masks, see what happens... Try overlaying patterns onto photos, photos onto patterns, try using the transparency lock and painting over text. If you are unclear about anything, just ask and I'll explain more.

That's all for now... Next time - Layer Styles!  

[Triskdaemon]

Well, I had intended to wait a bit before posting this, but I find myself with way too much free time. Therefore, I will talk about layer styles for a bit. Maybe get into filters if I have time.

Layer Styles

Layer Styles are very nice and poweful tools. You can access the layer styles menu through the button on the Layers Palette or through Layer>Layer Style. There are several different aspects to layer styles, so I'll start at the top of the list.

Blending Options

This is a more advanced version of the blend modes that I covered in my last post. In addition to the many and multifarious variations of blend modes, you can choose to exclude channels and change the options for interacting with a layer mask. This will allow you to make the layer do just about anything you want to with regards to blending with the layers below it. Play around with this one until you get the look you like.

Drop Shadow

A very useful little tool, this provides the illusion that the layer is separated from the layers below it by adding a bit of shadow. The blend mode and color are pretty self explanatory - how the shadow interacts with the surface that it falls on, and what color it is. Opacity controls the strength of the shadow. The light angle controls the direction of the light source that is casting the shadow. I would suggest using one direction of light for all of your effects and layers, just to keep the effect consistent. Distance is the simulated distance betwixt the layer and the one below it. Spread controls the sharpness of the shadow - higher values=sharper. Size is the... size. Of the shadow. Hmmm... Contour is the pattern that the shadow follows. By default it's a smooth fade out, but you can make it come in and out, or follow an exponential-type curve fade, getting cool liney effects. Play with that one, you'll get the idea pretty quickly.

Inner Shadow

The same as drop shadow, but this time on the inside of the image. Gives the impression that your layer is a hole or gap in the image. Try that one on text. All of the sliders work the same way they did in the drop shadow panel.

Outer Glow

This is a fun one. Gives a nice glowing effect all around the image. As before, the blend mode controls the interaction with the bottom layers, and the opacity slider controls the strength of the glow. You can choose either a color or a gradient for the glow, to give the glow some variation as it goes away from the object. The "Technique" widget is just a thing that controls the style of glow you get. Spread and size are similar to the shadow controls of the same name. The contour works the same way as well. Play with this on a black or dark background. You can get some really nice effects on text this way.

Inner Glow

As you may have guessed, this works the same way that outer glow does, but on the inside. All controls are the same, with the exception of the Center/Edge thing. That just controls where the glow emanates from, either the outer edges or the center. Also good for text.

Bevel and Emboss

This is by far my favorite one of the Layer Style tools. It gives the edges of the layer a raised look or a 3D appearance. First, take a look at the Styles available. It's set by default to inner bevel, which is a nice multi-purpose style. It gives a good, rounded look to things. Outer Bevel gives things a 3D look by modifying the area around the image instead of the actual image. This has its purposes, but I've always found it to be less useful. Emboss conveys the impression that the image has been punched outward from the rest of the picture, a pretty versatile style. Pillow Emboss is just flat-out cool. It gives the impression that the image has been inset into the picture below it, like this text:

Incidentally, the edge of the blade is also made with B&E, and the rust is pillow embossed onto it. This is a really good way to create a sense of integration between layers, so they don't look as if they are tossed over each other. The light source is as it always is, but I'm going to pay special attention to the contour portion this time. The contour is the shape of the bevel, as if you were looking at the edge from the side. Most of the time, it'll work pretty well with the flat contour, but play with the shapes! See if you can figure out how I made the blade up there... Going back up for a second, I'd like to point out the Depth, Direction, and Size options. Depth is the amount that the bevel goes in a "vertical" direction, or how deep your edge is. Size is the amount that the edge intrudes on your image, or goes away from it. Think of it as "horizontal" size. Direction simply reverses the direction of the bevel, so that it is inlaid rather than standing out. There are two sub-options there on the left menu, Contour and Texture. Contour is the specific contour for the gloss, not the physical curve of the object. Texture applies a bump map to the surface of the object, changing the specular patterns. This can look very cool, or very cheesy. Play with these options! There's nothing cooler than 3D in your images. This takes a while to get used to, however, so practice lots.

Satin

Satin has a lot of uses, especially in plastic or other reflective surfaces. It puts little reflective thingies all over your image, giving the impression of curvature and specularity. The sliders are pretty simple here. Distance controls the position of the reflections, and size controls the sharpness.

Overlays and Stroke

The others in the list are easy to use. Color Overlay overlays color, Gradient overlay overlays a gradient, and Pattern Overlay... Well, you can guess. Stroke simply outlines the image.

Well, that's all of the layer styles. I cannot stress enough how beneficial messing around with the things above can be. Practice gets you familiar with the program. Now on to...



Filters!

For now, I'll just run through the most useful ones, but I'll end up covering more later.

The most versatile one in the box is Gaussian Blur (Filters>Blur>Gaussian Blur). This is your multipurpose blur function, and ends up being necessary just about everywhere. A tip for this one is to blur it once, just a bit less than you want it. Then, blur at half that value, then at half that value... This resluts in a much smoother blur.

Another one that I love is Clouds (Filter>Render>Clouds). Clouds is there to give you random fractal backgrounds. This is how you start off a lot of things involving abstract backgrounds. Combine this one with Difference Clouds to get more interesting shapes. Difference clouds is like a combo of clouds and inversion. Play with it...

A really nice, yet unknown filter is the Anisostropic diffuse filter. Go to Filter>Stylize>Diffuse, and select Anisostropic. This will smooth out lines without blurring the edges too much. It will mess with detail in the image, but if you're working with a fairly basic picture with little detail, this is highly useful.

The photographer's friend is the Unsharp Mask filter (Filter>Sharpen>Unsharp Mask). This makes edges stand out and detail become more prominent. Just mess with the amount and radius sliders, those will give you your desired effect 99% of the time.

Well, that's it for now. I mean it this time. No updates until tomorrow. See you later, and mess around!  

[Chisa]

Oh wow. This is fantastic! I screw up pictures all the time, because use a LOT of layers, and don't organise or lock them properly sweatdrop And I never really got the Blending options or Layer Styles until now... I can see those being really useful in the future. Definitely a useful tutorial, thanks for taking the time to post it!  

[Triskdaemon]

Hey, that's the first time I've been called useful in a while... Anyway, the next thing I'd like to cover is another aspect of Photoshop that is often overlooked: Channels. Channels are accessable from the layers palette, the tab on the top that says "channels" will lead you to them. What channels can be used for, or at least their major use, is to create selections. To illustrate my point, I'm going to give you a small tutorial to make a stone background.

First, we'll set our colors up. Pick two stone-type colors and set them to foreground & background. Use the Clouds filter. Apply the noise filter (Filters>Noise>Add Noise) with amount at 6, gaussian distribution, and monochromatic checked. Then Gaussian Blur at 1 or 2 pixels. Now go to the channels palette and create a new channel - it's the same button as on the Layers Palette. Now set your colors to the default (D), and repeat the last steps, Clouds through the Blurring, in the new channel. Return to your normal layer. Now we go to the lighting effects filter (Filters>Render>Lighting Effects) and look at the bottom. Where it says Texture Channel, click and you should see your new channel in the menu. Select it, and turn the slider to Mountainous. Fiddle with the settings to get a nice look, and press OK. This is what I got:


Do you see how the channel interacted? The channel became a heightmap for the coloring, and created the stone effect.

Another use for channels is selection creation. You can apply effects over a certain area with this. Go back to your channel and put a white to black gradient over the entire thing. Then, go to Select>Load Selection and select your channel in the "Channel" menu. Click ok, then apply the chrome filter, or any other filter in the Sketch or Stylize menu. See how the channel affects the distribution of the filter? Try drawing on the channel or mixing up your gradient to achieve different results. Some uses for this:
-Applying selective blurring for a Depth of Field effect.
-Selective deletion and transparency
-Effect transitioning
-Text effects (like typing text in the channel...)

Another tip - Try putting chrome in the channel and blur it a bit, it creates a cool effect.

That's all about channels, more to come on all things Photoshop...
Questions and comments welcome.  

[Triskdaemon]

All right, I have the time to post more, so lets talk about brushes and tools. First, I'm going to cover brushes in the context of the paintbrush tool.

One of the things that makes a great image is to alter the brush presets and create your own brushes tailored to an image. I'll assume that you're using a later version of PS, if not, then the features that you have should still be the same as the ones here. Open up the brush editor palette (Window>Brushes). Look at the first option below the presets, tip shape. This is pretty simple, just the footprint of your brush. Choose a hard, fuzzy or odd-shaped brush. For this little guide thing, choose a nice, medium-sized hard brush. Now look at shape dynamics.

Shape Dynamics

This controls how your brush changes size. The first option is size jitter, which randomly varies the size of your brush, creating a blobby effect. Next, you can set options for fading and pen pressure (Graphics tablet stuff). By default, it's set so that lighter pen pressure creates a smaller dot. Alternatively, you can set it to respond to pen tilt or your stylus wheel. If you don't have a graphics tab, you can still use the fade option, the number next to it specifies the length at which your stroke goes to. Minimum diameter is simply the level to which your brush can be scaled down by the above options. There are similar sliders to affect the angle and roundness of the brush, both of which are hard to see with a round brush. Pick a calligraphic brush and look at the effects that those brushes have. Turn off the Shape Dynamics check for a bit.

Scattering

Such a fun option. This one randomly distributes your brush over an area. The scatter amount slider controls the distance the brush can land from your cursor, while the Both Axes check randomizes on both... axes... Funny how that works. There's an option to control the amount of scattering with your tab pen or by fading, just like the last one. There's a similar setup to control the amount of dots, or the count, below that.

Texture

This just acts like a clone brush, where you're using a repetitive tiled image as the source. Works in some situations and not in others. You can eliminate the tiling effect by checking the "Texture each Tip" box, this restarts each instance of painting at a different source point on the texture image, leading to a more diversified image. The other settings are pretty much self-explanatory.

Dual Brush

This sets it up so that your original brush is applied through another brush. The easiest way to think about this is that the first and main brush gets applied only where the dual brush would also put color. You can get some really cool effects here, so just mix and match brushes...

Color Dynamics

Here you can set your brush to bounce back and forth between the foreground and background colors, as well as adjust the jitter effect on hue, saturation, and other aspects of the color. Try combining this effect with the scattering and shape dynamics to get the effect in my siggy...

Other Dynamics

This allows you to get the opacity and the flow jittering around, pretty self explanatory.



That's the top part, I'll finish the rest later on.