This section is the most basic section—you need light for your photography.
This section is also the most advanced—light is a huge topic.
And, of all the sections, this is the one you'll want to refer back to often.
First, what's in this section can't be absorbed in one sitting, and a few photographs.
Second, light is the most important ingredient in a photograph.
The subject in front of your camera is less important than the light illuminating the subject.
For example, a scruffy dog in great light can look better than a dog-show champion in poor light.
William Henry Fox Talbot published a book of photographs between 1844 and 1846 called The Pencil of Nature.
Light is our pencil.
For example, in 1923, Ansel Adams wrote:
I was climbing a long ridge west of Mt. Clark.
I was suddenly arrested in the long crunching push up the ridge by an exceedingly pointed awareness of the light.
The moment I paused, the full impact of the mood was upon me.
I saw more clearly than I have ever seen before or since the minute detail of the grasses, the clusters of sand shifting in the wind, the small flotsam of the forest, the motion of the high clouds streaming above the peaks.
There are no words to convey the moods of those moments.1