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In some ocasions, I tried to do some direct colouring of a black-and-white photography with multiply option, a really easy technique, as you could read in some previous post.

However, sometimes the result in the screen is not matching the desired effect upon printing. Sometimes, it becomes yellowish, or rather quite reddish.

Original virados 3083 bn07525 cSp p virados 3083 bn07525 cSp Sepia p Sepia

Of course, this is produced by the (lack of) equipment callibration - in fact, I use to work with an USB portable GIMP version over different computers and printers.

A solution: at least, to fix some parameters in my workflow, so that results will be uniform.In this case, I propose the following values' table, which can be useful to produce image collections with a same colour finish between ll of them:

Colour R value G value B value
Sepia 112 66 20
Palladium 96 85 69
Cyanotype 78 121 154
Silver gelatin 130 118 105
Silver 119 122 123
Selenium 132 124 128
Platinum 124 121 115

The proposed colours match the traditional chemical processes used to colour photographies.

NOTE: those proposed colours are relatively dark; depending on your photography, you may get a better result when selection the fusion mode "Soft Lighten" instead of "Multiply"...

IMPORTANT

This is a quick technique, ehough for most cases; however, it does not simulate the original chemical processes properly.

As a fact, depending on the amount of chemicals (in paper or any other support), reaction is slightly different, so that highlights and shadows get different colour shades, too. We will need to work on curves adjustment per channel.

In a few days, I intend to post a new article on image colouring with a "professional" finishing with GIMP...

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Are you interested in curves and levels? In that case, don't miss my book "Levels and Curves with GIMP"

Cover 600x934 Amazon shop - paperback ebook

Tag(s) : #Photography