O pen a Raw file in Photoshop CC and it will automatically launch Adobe Camera Raw (ACR) in its own plug-in window (see below). The first thing to do is correct any lens distortions, such as barrel distortion from wide-angle lenses or pincushion distortion from using a telephoto optic. You’ll also want to fix any vignetting in the corners and chromatic aberration where bright purple or green colours appear in areas of strong contrast. It’s near impossible for a lens to not have any chromatic aberration, though premium lenses do a better job at mitigating this. The last of the initial tweaks is to apply a crop, as there’s little point working on areas that will be cropped out of the final image.