How to Render a Nebula and Star Field with Photoshop

Cue the Star Trek theme.

Images of nebulas and star fields are a treat to behold and can invoke poetic thoughts about the vastness of space, the nature of time, the meaning of existence, and the greatness of Star Trek. If you want a nice image of nebulas and star fields for your desktop or next sci-fi illustration, here is a relatively easy way to create your own nebula scene in Photoshop. It takes about ten minutes of work once you are familiar with the steps.

Difficulty:

Moderately Easy

Instructions

Creating the Nebula Clouds

1. 

   Create a file in RGB color mode at the size and resolution you want.

2. 

   Hit “D” to set your foreground color to black and your background color to white. Then, in the top menu bar, pick "Filter --> Render --> Clouds" to create a black-and-white cloud background. This will become the nebula.

3. 

   Click on "Image" in the top menu bar. Pick "Adjustments," then "Hue/Saturation." In the dialogue box, check the "Colorize" box, then drag the "Hue" and "Saturation" sliders until you get a nice blue (For this example, set the Hue at 229 and the Saturation at 44). Rename this layer “Blue clouds.”

4. Create a copy of the “Blue clouds” layer by clicking it in the "Layers" palette and dragging it over the “Create a new layer” icon at the bottom of the palette. Rename the new layer “Red clouds.”

5. 

   Repeat Step 3, but this time, give the clouds a red tint (0 for hue, 47 for saturation).

6. 

   Select the "Red clouds" layer in the Layers palette and click the “Add layer mask” icon (white circle) at the bottom of the palette. You will notice a layer mask thumbnail appearing next to the layer thumbnail in the palette. Click on the mask thumbnail to make sure you are working on the mask.

7. 

   Select the "Gradient Tool." Pick a linear, foreground-to-background gradient. Set the gradient blending mode to "Multiply." Make sure your foreground color is white and the background color is black. Click and drag from one spot to another to create a smooth transition between the “Red clouds” layer and the “Blue clouds” layer. Add as many gradients as necessary to get the transition you want.

Creating the Star Field

1. Create a new layer on top of the two clouds layers by clicking the “Create a new layer” icon on the Layers palette. Name it “Space.” Fill it with black.

2. 

   Add a layer mask to the “Space” layer and draw several gradients on it to get something similar to the sample image, with clouds occupying part of the image and black space filling up the rest.

3. Create a new layer on top of the “Space” layer. Name it “Small stars” and fill it with black. Then go to "Filter --> Noise --> Add Noise" in the top menu bar, and use the following settings: 10%, Gaussian, Monochromatic.

4. 

   Go to "Image --> Adjustments --> Brightness/Contrast" in the top menu bar. Set Brightness to "-50" and Contrast to "85" to make the stars more visible.

5. Go to "Image --> Adjust --> Levels" and move the left slider until you get the desired amount of stars.

6. Change the layer blending mode for the “Small stars” layer to "Linear Dodge." This allows the layers below to show through.

7. Make a copy of the “Small stars” layer by dragging it onto the “Create a new layer” icon. Rename the new layer “Large stars.”

8. 

   Hit "Ctrl-T" and you will see a bounding box with handles on the sides and corners. Click and drag those handles to enlarge the layer, holding down "Ctrl" to resize proportionally. Hit "Enter" when you have enlarged it to the point where the stars on this layer are visibly but not significantly bigger than the “Small stars” layer.

9. Make the big stars brighter by going to "Image --> Adjust --> Brightness/Contrast." Set Brightness to "-100" and Contrast to "90."

10. 

    Hide the stars that are overlapping the nebula by applying a layer mask on the two stars layers. We can re-use the one we made on the “Space” layer. Click on the mask thumbnail on the "Space" layer. Hold down the "Alt" key and click and drag the mask thumbnail onto the thumbnail for the “Small stars” layer. Repeat for the “Large stars” layer.

Extra Touches

1. Add a twinkle to a couple of the large stars. Create a new layer on top of the “Large stars” layer and call it “Twinkle.”

2. 

   Select the "Brush Tool." Go under the brush picker. Click the small triangle icon and pick “Assorted Brushes” and select “Append” in the dialogue box that pops up. Pick the "Crosshatch brush."

3. 

   Set your foreground color to white. Adjust the brush to an appropriate size and set opacity to 100%. On the Twinkle layer, move the cursor so that it’s centered on one of the large stars. Then click to paint the crosshatch over it. You can click a few more times without moving the mouse to make the twinkle brighter.

4. Switch back to a soft round brush and move over to where you painted the crosshatches. Add a little soft white circle to the center of the crosshatch.

5. Add a new layer and call it “Flare.” Fill it with black and set the blending mode to "Linear Dodge."

6. 

   Go to "Filter --> Render --> Lens Flare." Set the desired flare location, brightness, and type.

7. 

   Use a layer mask on the "Flare" layer to hide the flare's halo and glare if they spread out too far. Create a mask on the “Flare” layer. Choose the "Gradient Tool" and use a radial gradient. With white as your foreground color and black as your background color, click at the center of the flare and drag outward. Wherever you stop, that’s where the flare will stop.

Tips & Warnings

• We only used the "Gradient Tool" while working on layer masks in this example, but you can use any drawing tool in Photoshop to change your masks, such as the brush tool, which gives you more control over particular areas of the mask.

• You can add more star layers if you wish. The more layers you add, the more varied the size and placement of your stars will be.

• If you are creating this image for print, the final image will need to be in CMYK instead of RGB. However, do all your work in RGB and only convert to CMYK after you have completed the steps and flattened your image. If you convert the color mode without first flattening the image, the colors and layer blending effects might change significantly.