These are optical flaws produced by camera lenses and which are largely unavoidable except in the most expensive or the simplest lens designs. They include distortion, chromatic aberration (colour fringing), vignetting (corner shading) and edge softness.
Editing A-Z
Adjustment layer
A special type of layer in image-editing software which is designed to hold adjustments rather than other image layers. It’s a way of ‘stacking’ a series of adjustments to an image without affecting the image layer itself.
Adobe Camera Raw
Software that works alongside Adobe Photoshop to open and process RAW files before they open in Photoshop itself. Adobe Camera Raw’s tools are also built into Adobe Lightroom. Most people use Adobe Camera Raw to process their RAW files simply because they’re using Photoshop or Lightroom, but other RAW converters are available.
Adobe ProPhoto RGB
This is a wide-gamut ‘working space’ used in Lightroom and other Adobe software. The idea is that it encompasses all the lesser working spaces you might need to produce images in, such as sRGB or Adobe RGB.
Adobe RGB
This is a professional colour space offered by more advanced cameras and it captures a slightly wider range of colours than the usual sRGB colour space used by most consumer devices. It can be useful if pictures are destined for commercial print production, but it does introduce complications with colour profiles and monitor calibration.