Learn HDR in Photoshop, Colin’s HDR photography tutorialColin Smith What is HDR and why do we need it?I n this tutorial we will take a look at HDR photography. HDRI (High Dynamic Range Imaging) was originally used in 3D and is now in full force in photography. Basically it’s the process of taking multiple exposures and merging them together into a single 32 bit image. Let me explain: Watch the HDR