Photoshop Tutorials: Add A Realistic Rainbow To A Photo

Step 11: Duplicate The Rainbow Layer To Increase Intensity

If you want to increase the intensity of your rainbow, which I do in this case, simply press Ctrl+J (Win) / Command+J (Mac) to duplicate the layer. You'll probably find the rainbow is too intense at this point, so reduce its intensity by going up to the Opacity option in the top right of the Layers palette and lowering the opacity of the duplicate layer. I'm going to lower mine to about 70%:

Here's my image after duplicating my rainbow layer and then lowering the opacity of the duplicate layer:

Step 12: Duplicate The Rainbow Layer Once Again And Move It To The Left

The rainbow is looking good at this point, but I want to add a double rainbow effect. To do that, I'm going to press Ctrl+J (Win) / Command+J (Mac) once again to create another duplicate of the rainbow, so I now have three rainbow layers in the Layers palette:

Step 13: Move The New Copy Of The Rainbow Layer To The Left

Grab your Move tool from the Tools palette, or press M to quickly select it:

Then simply click anywhere inside the Document Window and drag the new copy of the rainbow layer to the left or right to create a double rainbow. Hold down Shift as you drag to make sure you're dragging horizontally. I'm going to drag mine over to the left:

Step 14: Re-apply The Gaussian Blur Filter To The Second Rainbow

We don't want this second rainbow to be as intense as the original, so press Ctrl+F (Win) / Command+F to quickly re-apply the Gaussian Blur filter using the same Radius value we used previously. You may want to press Ctrl+F (Win) / Command+F (Mac) a second time to lower its intensity even further. I only need to apply the filter once with my image. Here's my image after lowering the intensity of the second rainbow. It's less intense but still noticeable in the corner of the photo:

You can also change the opacity value of the second rainbow in the top right of the Layers palette to make further adjustments to its intensity.