Dodge and Burn Explained
I know I am dating myself here, but I recently received an invite for my 20 year highschool reunion. Twenty Years... when did that happen? Anyways... I still remember taking all the pictures for our yearbook. Believe it or not, there was no digital "back then", and I spent long nights in the darkroom processing - good times.
Why am I talking about this? Sometimes it's good to go "back to basics" - Photoshop, Lightroom, etc are basically digital darkrooms. Their tools and terminology are heavily based on analog (old school?) photographic processes. Today, as an example, I would like to explore where the terms Dodging and Burning come from.
Well, first of all, what is it? On a high level, the two tools are used to lighten or darken parts of your image, in order to improve tonal reproduction (contrast) in images. These two techniques are, in fact, such important aspects of photography, they were considered a major feature of the early versions of Photoshop.
Ansel Adams developed dodging and burning into an art form. Many of his famous prints were processed in the darkroom with these two techniques, and he wrote a comprehensive book on producing prints called... well... The Print, which features dodging and burning prominently, in the context of his Zone System.
In the dark(room) ages, after you developed the firm and got your negative, you need to create a print using a device called an enlarger (I just saw they even come in different colors nowadays? Fancy!). You would put your negative in the top part, the paper on the base plate, then shine a light through the negative, effectively projecting it on the paper. The longer you exposed the paper, the "darker" it would get.
That's all great as long as you had a perfect negative, and didn't care about having some creative freedom in "post-processing" your prints. Lets say you wanted to "lighten" parts of your image, which means "giving parts of the paper less light than the other parts" during the exposure.
The easiest way to do that was to take a piece of cardboard, and place it between the negative and the paper, moving it around a bit so you didn't get any ugly edges. This was called "dodging". How long you covered an area, the shape of the mask or its material (translucent? solid?), were all variables of personal preference, experience, and creative expression.
"Burning" followed the same principle, except you try and overexpose parts of a print to darken the area. So one first did a normal exposure, then mask the print so only the area you want to darken is exposed to light.