Why is the effect called Dodge?

Darkroom manipulation

The term originates in the photographers dark-room, and sadly I am old enough to have literally “dodged and burned” photos under the enlarger!

An “enlarger” is simply understood as a projector. It beams light through a negative and onto photographic paper. In much the same the way the lens of the camera “printed” the light onto the negative in the first place.

While this process is happening (and it takes a few minutes depending on exposure), you have an opportunity to vary the amount of light hitting the paper in different parts of the photograph. These techniques are called “dodging” (blocking light from an area) and “burning” making more light hit only a certain area (or blocking light from everywhere else if you will!)

The icons in Photoshop are amazingly accurate. A “pinched” hand to let more light through whilst covering the rest of the image (if supplemented by cardboard), and cotton wool on a stick will hold back light from a desired area – it simply “casts a shadow” and stops the light from hitting the paper.

Dodging
Dodging can be used performed using the hand or specific tools such as black cardboard. Dodging is best when used in a circular motion on the image to get the desired result. Dodging over an area has the effect of lightening that area. Specifically then – to answer the question – “Dodging” refers to the paper dodging the light (by way of a blocking mechanism)

The technique I was taught involved moving cotton wool on a stick randomly (difficult) over the area where I want to hold back light

Burning
Burning is when the image receives more light (exposure) so the image can darken. Just like dodging, burning can be done by hand or by using objects that control the size and shape of the area. To avoid visible steps between the burned-in area and the rest of the image, the device should stay in motion.