What is fog? We are going to show you different ways of inserting fog into our renders using photoshop. Fog is a type of cloud that touches the ground. There are many types of fog, it depends on the day, the geography, there is fog with rain, fog with summer, fog with winter, fog with smoke, etc.

Reference Study

First, we do need to understand how fog works, and how it plays an important role in our renders. We did a reference study of different fogs used in renders.
We found that fogs:
- Don’t always have to be white
- Have a grainy look
- Help define depth and contrast
- It doesn’t mean less attention to detail
- Thin layers of fog help separate, background, middle ground, and foreground
- It is emphasized when put in contrast with fogless elements.
- Adding fog doesn’t mean the sky has to be grey.
- The majority of the time, there is always a thin fog in the air.
Method 1

In this image, we already have different fog images, but we wanted to add a subtle fog to it.

We have some fog brushes, and we are going to create a new layer. The idea is to put this fog to separate the person from the background, make it stand out.

Since we want to make the character stand out from the background, we will be adding a subtle fog to the middle ground but not touching the character, so we click on the person, and pressing ctrl to select, then ctrl+shift+i to invert and start adding fog to everything but the person.

Also, it is important to see where you will be putting the fog so it can also give that depth look. then press ctrl + D, to deselect and see the final result
Method 2

With our image in photoshop, we create a new layer and then we go to Filter > Render > Render clouds

We can see the type of clouds that photoshop is going to give us, so the key is to change the blending mode to screen.

After putting the blend mode on screen, we can see clearly but obviously, it is just too much, these clouds are too out there, and it is not even inside the image, it is just out there.

So we are going to create a mask to hide all of the clouds, then pressing ctrl + i, everything is hidden and we are going to use some brushes (B) to start revealing the clouds that we’ve just hidden.

So we are basically using the new layer to paint in the clouds that are hidden and paint them with the brushes. Remember to alternate between size and opacity.

If your fog is too white, then creating a new layer and using the eyedropper tool, you can select a color from the background image to make it your fog color so it can blend in with the background color.
Method 3

This is the easiest and fastest way of adding fog to your renders. So what we do here, is group all of the elements into one layer, and make it a smart object.

Now we go to filter > camera raw filter > dehaze. Just turn the dial to the left so you can have a lot of fog, if you go too much to the left, you will see it really burnt out.

Be careful and do not overdo it. You don’t want your image to look like this.
Method 4

This is the most used way, it is using a depth map. When you are in a render engine, lumion, vray, you have an option to export the depth map, that it looks like this. So, the white part is the part that is closest to the camera and the black part is the one that is farther away.

So we press ctrl+i to invert it

Then we set the mode to screen and we just lower the opacity
Extra tips

We know that in real life we see that fog has a whitish color, but this is what we want to avoid in our image. So please try to use the eyedropper tool to choose from the image a color so the fog can blend in.

In filter, adding noise, we want the fog to have this grainy look, but of course, don’t overdo it.

The other tip, try not to use only one layer. Use different layers for your background fog, middle ground fog, foreground fog, so you can have much more control over the fog.
How do you normally do your fog to add them to your renders? Give us some ideas! Watch the video tutorial below!