Introduction: This is a Photoshop tutorial for intermediate users. To use and understand this tutorial completely you should already know how to use certain Photoshop techniques, including where to locate tasks in the program. Of course like any other tutorial you need patience.
It’s best if the photo does not have a lot of sun in it. Obviously the image would look odd with both rain and sun in it at the same time. Also, sometimes to get good results you should make the image a tad bit smaller (especially in this case). I prefer to work with the image around 600×800. You can choose to work with a fullsize image of course, just understand that the rain will only look good when the image is viewed full sized to do the fineness of the rain drops.
Step One: Open up the image you want to work with on a blank canvas in Photoshop. Flatten this layer if it’s not flattened already. You need to start out with only one layer instead of the image and the canvas layer.
Step Two: Next duplicate the layer now so you have the same image twice. (Layer>Duplicate Layer).
Step Three: Go to Filter>Noise>Add Noise. Set the amount to about 15%. The higher the amount, the thicker the rain so you can set this to whatever you feel is best for your image or taste. Make sure the distribution is gaussian and that the monochromatic box is ticked, otherwise your rain will be rainbow colored and look odd.
Step Four: Now go to Filter>Blur>Motion Blur. The angle should be at about 70, and the distance should be around 10. This will give you a nice stormy effect.
Step Five: Put the rain layer on Lighten. This will lighten the top layer and make it slightly transparent to the bottom one. This is when you’ll start to see the rain effect on your image.
Step Six: This time flatten the two layers together so they become one. Then duplicate the flattened layer again making two new and similar image layers.
Step Seven:Image>Adjustments>Desaturate the top layer. This should leave the top layer black and white only.
Step Eight: For the top desaturated layer, go to Filter>Blur>Gaussian blur and put it on a radius of 2 pixels.
Step Nine: Put the top layer on Soft Light, and then your image should have a rain effect and a slight glow effect as well.
Then you’re done and you have a realistic looking rain effect on your photo. Step Six-Eight are not neccessary, but add a nice glow effect in Photoshop.