The Astrophotography Manual, 2nd Edition

Image Stretching

Just as when a print emerges from a tray of developer, this is the magical moment when you find out if your patience has been rewarded

 

 

Following on from the chapter on noise and sharpening, stretching is the logical step into the non-linear workflow. This is the magical moment when faint details are made permanently visible and the fruits or your labor become apparent. The familiar automatic screen stretch that we use for assessing manipulations on linear images can be applied to an image but rarely gives optimum results. The golden rule is to not over-stretch. Although global stretching is frequently required to set a baseline, it is often the case that further manipulation requires selective application. Stretching ...