NOTES – Editing

NOTES includes short papers and test files abridged from our workshops and consultations that address the most commonly asked questions.

Calibrating                    Printing                    Editing

Updated 17 November 2024.

  THEORY  

  APPLICATION  

  PRACTICE  

Luminosity Mapping

The conversion of multi-channel images to a single greyscale channel is based on a luminosity formula, which in turn is based on a theory of perception. This paper examines Photoshop’s methodology and why desaturation and other conversion formulae do not always produce a satisfactory perceptual result. Last updated 24 May 2014.

Converting to sRGB

An outline of the real world problem when converting from large gamut Matrix profiles to smaller gamut Matrix profiles, such as from ProPhoto RGB to sRGB, and our LUT based sRGB profile’s perceptual gamut compression aesthetic and workflow solutions. Last updated 21 June 2020.

Editing Out of Gamut Colours

A method for the local perceptual compression of Relative Colorimetric (B2A1) ‘out-of-gamut’ transformations using the L*a*b* colour model, as implemented in applications like Affinity Photo and analytical tools like ColorThink. Last updated 8 October 2020.

B&W Contrast Filters

The comparison and calculation of digital equivalents to the Kodak Wratten Filters most commonly used in pictorial photography, and their application in file preparaion for printing digital B&W fine prints. Last updated 13 June 2020.

Matching Colours to Reference

LUT based colour correction is image independent so almost any colour palette or image can be sampled and used as the basis for the colour rendering of other images. Last updated 13 October 2020.

Resolving Encoding Errors

A brief analysis of Adobe Photoshop’s colour encoding issues and workarounds to resolve the colorimetric confusion and frustration when commonsense fails us. Last updated 28 June 2021.