Image overlay pattern comes in very handy when a website has a full screen image or a video as a background. Applying a pattern can make things more readable and easier on eyes. Let's Photoshop.
Remember as a kid you played with a mirror, putting your face to the side of it and your friends were laughing at the funny symmetry of your face and your faces reflection?
A simple Photoshop tutorial, where you may learn how to expose an object by leaving it in color while turning the rest of the photo black and white or sepia.