Adding rain digitally can increase the drama in a photograph and it can even make it look more realistic. Often when photographing in the rain, the rain doesn't appear in the photograph. Here's an effective way of adding realistic rain by utilizing several layers of rain.
 |
1. Open the image for editing. For this tutorial, select an image with a cloudy or overcast sky. Use the default forground and background colour (D). |
 |
2. Duplicate the layer "Background" (Ctrl+J) so that there are 2 layers. |
 |
3. On the layer "Layer 1", apply a "Grain" filter (Filter> Texture> Grain). Set the "Intensity" to "55" and the "Contrast" to "50". Click OK. |
 |
4. Apply a "Motion Blur" to the current layer. Set the "Angle" to the direction the rain is falling and the "Distance" to the speed of the rain. |
 |
5. Duplicate the layer "Background" (Ctrl+J) and move it to the top layer. Add a "Layer Mask" (Layer> Add Layer Mask> Reveal All). |
 |
6. With the top layer selected, use the "Apply Image" tool to apply the following properties:
Blending: Normal
Click OK. |
 |
7. Change the blending mode of "Layer 1" to "Overlay". |
 |
8. Create a new layer as the top layer (Shift+Ctrl+N) and fill the canvas with the colour white (Ctrl+Enter). Apply a "Grain" filter (Filter> Texture> Grain) with the same properties as step 3. |
 |
9. With the top layer selected, apply a "Motion Blur" (Filter> Blur> Motion Blur). Use the same "Angle" you've used in step 4 but set the "Distance" twice the pixels you've previouslyused. |
 |
10. Set the blending mode for "Layer 1" to "Overlay" and set the blending mode for "Layer 2" to "Linear Dodge". Set the Opacity for "Layer 1" and "Layer 2" to 50%. |
|
11. Your image now looks like it is raining. Rollover the image on the left of this step to see the original image before this technique was applied. |
Try different settings in steps 3 and 4 to get different types of rain. Reduce the "Intensity" of the "Grain" filter to reduce the amount of rain.
More Tutorials: 
