I saw somebody ask about this effect on a forum, and I thought it might be fun to play. I can’t imagine anybody will ever use it, but hey, it’s the weekend, why not mess around?
Start by making a Gradient layer:
By default it will probably give you a black-and-white gradient …
… but you can choose a rainbow instead:
NOTE: If you can't find the rainbow option in your version of Photoshop, follow these instructions.
I also changed the angle and the scale a bit:
NOTE: Always check the "Dither" box, to prevent the risk of banding.
Now the image looks like this:
Play around with the layer blend modes. You’ll probably choose "Color" mode. Also adjust the opacity if necessary:
Now make a Solid Color layer:
And choose black:
Invert the mask on that layer from white to black, to hide the black colour on the image:
Then choose an enormous soft brush, and gently paint with white on the mask around the edges to add that aggressive vignette:
If you have a question about this article, please feel free to post it in Ask Damien.