You can use blending modes on layers to create effects unique to digital art, such as dazzling light effects. In this article, I’ll use examples to show you how to create different kinds of light effects.
Read to the following article to learn about the blending mode feature.
 Expressing light
Let’s try out some blending modes in a scene with a light effect.
I’ve drawn the below light beam at 100% opacity. (Layer Name: “Effect Line”)
If I set the blending mode to [Normal] and stack the “Effect Line” layer on top of the picture, it completely hides parts of the lower layer.
Let’s set the blending mode of the “Effect Line” layer to [Add (Glow)].
Now I can see more of the below layer “Dog”. This is another way of making a layer transparent other than lowering the opacity.
I copy the “Effect Line” layer and paint over it in white, then go to the [Filter] menu > [Blur] > [Gaussian blur]. (Layer Name: “Effect Line Blur”)
I set the “Effect Line Blur” layer to [Add (Glow)] to make the light look more brilliant.
I then lower the opacity of the blurred layer to adjust the impact of the shine.
 Difference between blending modes
Each blending mode has a different effect on the layers below.
Here’s an example where I changed the blending modes of layers “Effect Line” and “Effect Line Blur”.
The brightness of the light in A and B is slightly different.
Now let’s see what happens against a dark background.
When set to [Glow dodge] like in A, the light doesn’t show in areas that are close to black. If the lower layers are in colors close to black, then [Add (Glow)] will give a brighter effect than [Glow dodge].
Use [Glow dodge] if you want to use the colors on lower layers, and use [Add (Glow)] if you want to add a light effect on top of the lower layers.
 Controlling shadows
You can also create a range of different expressions for shadows using blending modes.
If you change the brightness by going to the [Edit] menu > [Tonal Correction] > [Brightness/Contrast], and lowering the [Brightness], the overall image will get darker, but you cannot adjust the shadows in different areas.
So, I’ve drawn the shadow on a layer above. I made a gradient from white to black. (Layer Name: “Shadow”)
Let’s try changing the blending modes of the “Shadow” layer.
In example B with [Linear burn], there’s a distinct contrast between the dark and light parts (the color is richer).
■ Using color
You can also use blending modes to create shadows with color.
I set the blending mode of these colored shadow layers to [Multiply].
The overall tone of the image changes greatly depending on the color of the shadow. You can also use a [Pen] tool instead of gradation to add shadows where you need.
 Controlling brightness
Let’s try adjusting the brightness in the same way as the shadows by using blending modes on the top layers.
I prepare a layer on top with a black-to-white gradient. (Layer Name: “Brightness”)
I set the blending mode of the “Brightness” layer to [Screen]. Only the white part of the gradient affects the lower layers, so it increases the brightness in a specific area.
This time I set the blending mode of the “Brightness” layer to [Overlay]. This makes the contrast stronger. The parts under the black gradient get darker, and the parts under the white gradient get lighter.
■ Using color
Let’s try another “Brightness” layer in a colored gradient like the one below.
I set the blending mode of the “Brightness” layer to [Screen].
In [Screen] mode, the white part hides the lowers layers, and the colored part changes the color of the lower layers while leaving them visible.
This time I set the “Brightness” layer to [Overlay].
The part that turned white when the layer was set to [Screen] becomes more strongly contrasted. The colored part also has an effect on the lower layer.
When set to [Overlay] mode, both white and dark parts of the layer will affect lower layers.
Let’s try with a different color scheme for the top layer.
You can using different blending modes and colors on higher layers to adjust the contrast and brightness in certain places, and to create different effects using color.
■ Increasing contrast
You can use the [Overlay] mode in a special way to increase the contrast in places.
[Original Image] (Layer Name: “Letters”)
I create a “Letters” layer and set the blending mode to [Overlay]. When I put this on top of another layer, the contrast increases only under the black parts and blurred parts.
You can create strong contrast in certain areas without changing the original image by drawing on a higher level with a drawing tool in black.
 Using blending modes
I’m going to use the special features of some blending modes to make pictures with a glow-in-the-dark effect.
I’ve prepared a completely black layer for the background. On a different layer (“Star” layer), I use the [Decoration] tool > [Star A] to draw stars, and I set the blending mode to [Add (Glow)].
It’s a bit dark still, so I duplicate the “Star” layer.
I duplicate until I have three layers, creating a bright effect.
On top of that, I make a new layer to add color (“Color effect” layer).
I try some different blending modes on the “Color effect” layer.
Creating effects with the [Brush] tool is also interesting.
I add a rainbow gradient on top of the original image and set it to [Overlay] (A)
I duplicate the original image and set the blending mode to [Add (Glow)], then adjust the brightness (B).
This is what it looks like when I layer A and B.
With the blending mode [Overlay], the brightness of lower layers affects the color of the higher layers, so you can create really interesting effects. Try them out for yourself to create all kinds of light effects.