Create a background for a space scene

In the future i plan to publish a few tutorials with various space scenes and i've decided to make this guide so that i wouldn't need to repeat the same thing every time. This tutorial will teach you how to make a starry sky and add the nebulas (gas clouds). Depending on the scene you'll be working on, you might need only stars or both the stars and the clouds. In any case you'll be able to refer to this guide and create your basic space background. So create a wallpaper size document (mine is 1280x800) and begin.

Step 1 - The stars

You should now have a new document with a single layer open. Fill that layer with black (press D for default colors and then ALT+BACKSPACE to fill). Go to Filter > Noise > Add Noise .... Use these settings for the noise:

Now the result of this operation will be a black background full of random white dots. That doesn't look like stars at all. To make it look more realistic we need to darken the darkest white dots and lighten the lightest dots. That can be done with levels filter. So open levels by pressing CTRL+L. Play with the left and right sliders until you get something that looks pretty good. Here's my configuration:

As you can see, the number of stars has increased dramatically. Go to Filter > Blur > Gaussian Blur ... and apply a 0.3 pixel blur. Next thing to do is create a little larger stars. The procedure is almost the same. Create a new layer, fill it with black, add the noise with the same settings. This time use levels to leave even less stars than before. Here's my settings:

With the second layer selected, press CTRL+T to transform it. On the top of photoshop window you'll see a settings panel for the current tool. Click on the chain icon to lock proportions, then click on the W letter and drag your mouse to the right to resize the layer. I've done a 133% change:

Click the little tick icon on the right side of the same panel to apply the changes (ENTER on your keyboard might do the same). So now we have two layers with different kinds of stars. Select the large stars layer (should be selected already) and change its blending mode from normal to screen. Now we are able to see both star layers at once. Press CTRL+E to merge the second layer with the first. Now we're going to add some shiny stars. To do that, select a soft 5px brush and change your foreground color to white. Now create a new layer for the stars. Press Window > Brushes, check the Shape dynamics checkbox and apply these settings:

As you can see, you only need to change the Size jitter to a 100%. This might be too much and if you need more larger stars, use 50% instead. Now with the current brush and the new empty layer selected, start painting the stars by clicking randomly on the document. When you're satisfied with the result, press CTRL+J twice. That will duplicate the current layer two times. Select the topmost layer and go to Filter > Blur > Motion Blur .... Use these settings:

Now select the layer below the current and add this motion blur:

As you can see, only the angle has changed, everything else remains the same. If you've done everything right, you should end up with stars like these:

Now you have a black layer with the simple stars and 3 layers with our advanced stars. Select the 3 topmost layers and merge them together (CTRL+E). Now create a new layer between your simple and advanced stars layer and fill it with black:

Now only the advanced stars are visible, but it's OK: we'll change it later. Select the topmost layer and press CTRL+E to merge it with the black layer. We've done this so that we could apply levels to the stars. So press CTRL+L and play with levels until you sharpen the stars a little. Here's my settings:

Now select the top layer, set its blending mode to screen and press CTRL+E to merge it down. Once again we are left with only one layer of stars that look something like the ones below:

That's the basics for the starry sky, now let's get to a more difficult part.

Part 2 - The nebula

To create gas clouds, we will need a couple of custom brushes and this is not something i can tell you how to do. You will never achieve the same results as i will so don't try! This will be a completely random process, that depends on your taste. I will only provide some pointers on what i've done, because it's pointless to write exactly what i've done: it's impossible to repeat anyway. Let's create the brushes first and then i'll walk you through what i did to make the clouds. Press on the picture below to open the cloud brushes tutorial and, following the instructions, create clouds brush # 1 and clouds brush # 2 if you haven't done that yet.

After this unpleasant and uncreative work is done, we can start painting our nebula :) Create three layers and name them white, blue and red. We will draw clouds in 3 different colors. As you'll see later, we don't really need those colors so it doesn't really matter much what colors you'll use, because what we're trying to achieve here is different color intensities. Here's how i've drawn the clouds: i've done that with the clouds 1 brush in 3 movements for each color, clicking on the left side of the document and releasing the mouse on the right:

Remember to draw each "line" on a separate layer. When you're done, merge the 3 layers together. That's what i got:

Doesn't look anything like we need right now, but we'll change that. As you can see, the white part of the clouds looks pretty good and real so you can use this brush in your other projects. OK, let's continue. Next thing i've done is desaturated the clouds by pressing CTRL+SHIFT+U. Next i've increased the contrast with curves (CTRL+M). I've created an s-curve that looks like this:

If you don't know what curves and levels are, please refer to my basic photo postprocessing tutorial. So after applying the curves, i had something like this:

I've decreased the opacity of the clouds to about 40%. Then, on a new layer, i took a white 30% opaque clouds 2 brush and started painting in the highlights. Then i changed the brush tool to the dodge tool and started dodging the highlights with the same clouds 2 preset and an exposure of about 20%. Then i switched to the burn tool to add some shadows. Here's what i had so after doing this:

Then i've added some color with the hue-saturation filter (CTRL+U):

So i've given the clouds some color and so far we have a pretty dramatic view. It's good if you want to emphasize the clouds, but if you need all of this just as a neutral background - that won't do very well. To make it more neutral, i've added a mask on the clouds layer and masked some parts of it, using my clouds brushes. If you don't know how to mask the layer, refer to my non destructive deletion with layer masks tutorial. After masking the clouds, i dodged some parts once again and finally came up with this result:

So there you have it - a starry sky with some gas clouds. A good background for your space scene.