Virtual Copy
An additional set of processing instructions attached to one source file, allowing several interpretations without duplicating data.
Measured in
count
In depth
Because only the instructions are duplicated and not the image data, a dozen virtual copies cost a few kilobytes. This makes it practical to keep a colour version, a monochrome version and a heavily cropped version of the same frame side by side, and to compare them directly rather than by memory.
Examples in practice
Three virtual copies of one portrait hold a neutral edit, a warm grade and a black and white conversion.