Light carries information, reflected light carries information about the object that is “lit”. There have been some false starts. Leonardo DaVinci, one of the most careful observers that has ever been, got this one wrong. DaVinci was pondering the eye, and how the eye saw the world. In his long observation he saw that there was a “light to the eye” in all living creatures. As an artist he was careful to illustrate this “light.”
Dead creatures had “dead eyes”, no light, DaVinci thought that a live creature with eyes, projected a “searching ray” out of the eye to all things visible, similar to a scanner, then brought that information back to the eye, therefore sight.
Thankfully, the truth is simpler. Light falls on objects without regard to a living eyeball nearby. Light then bounces off the object in all directions, just in case there is an eyeball around in order to be seen. What is confusing is that everything reflects the same light. Light beams carrying information are criss-crossing everywhere, each projection having an effect on each other. It’s a wonder that we resolve all this bouncing light into an image at all.
It is theorized that the scientific phenomenon of “camera obscura” could have been witnessed in prehistoric times. All you have to do is hide yourself in a pitch dark enclosure (a cave?), then poke a hole through to the light outside. The light comes through bringing information that can be seen (projected) on the opposite wall. Everything works better if the opposite wall is a light color and smooth. But hey, this could happen naturally. The image is recognizable even if it is upside down.
This is exactly what happens in the human eye. The image goes through the lens, and is projected on the retina, therefore we see. It is a little stomach churning that we see everything upside down, but our brain flips it, and reverses it. Thank you!
Artists have had to deal with creating art that “reflects” what we actually see. The difficulty is that it took a long time to solve some of the problems of rendering what we see. We didn’t solve “perspective” until the late Middle Ages.
We had the concept that little things were far away, and big things are closer. But we also had the belief that important things should be bigger than unimportant things. That makes for some confusing art. Everything seemed like paper cutouts glued on the canvas. Perspective could have helped, and finally, it did!
And then we have Masaccio’s disciple, Paulo Uccello, 1397-1475.
All this to say, because of the willingness to learn perspective and “foreshortening”, the artists produced paintings that looked more like the world that we see. By 1601 we had this painting by Caravaggio, Supper at Emmaus…
The artist landscapes of the time had the same issues. The paintings didn’t have the same “perspective” of what we could see.
So the artist used science, and constructed a light-safe tent, created an aperture, and used a mirror to reverse the image and projector it down to the drawing table. They were living inside a camera, and tracing the image that they saw. Landscapes suddenly were a lot more realistic.
Now, the problem is to capture the projected image without manual tracing it. The problem is best broken down in four steps
1. have a solution that reacts to light
2. Stop the reaction for a perfect exposure
3. Fix the image so that future light won’t effect it
4. Have all this on a medium that will give it good resolution.
All this was done within a fairly short period of time.
