What Is Full Manual Exposure Control?

In the days before autofocus cameras, there was a type of camera that made the photographer work for his or her photos. These cameras allowed the photographer to become highly skilled at his or her art and created some of the most famous photos in history.

History

The first cameras that produced good photographs were made in the mid-1800s and became famous largely by photographers such as Matthew Brady in the American Civil War. These cameras were big. They had a board on one end with a lens, a bellows in the middle that could be moved toward or away from the photographer to focus and a ground glass focusing screen on the other end. Tthe whole contraption sat on a large wooden tripod. The photographer put a dark cloth over his head to see the focused image, then inserted a glass plate coated with light-sensitive chemicals. When it was set, the photographer generally just removed the lens cap and counted out time to take the photo.

Function

There was a lot of guesswork involved in this early stage of photography. Eventually, glass plates changed to plastic negatives, the lens cap was replaced with a shutter and the light meter came into being. The shutter originally was a mechanical device designed to open and close the lens at a set speed. The faster the shutter speed, the more action could be "stopped" for the photo. Shutters ranged from one second to 1/500th of a second at the peak of the mechanical era. The light meter, which came into use in the 1920s, measured the amount of light at a scene and had dials that could be aligned with the moving needle to figure out the aperture and shutter speed required for a proper photo. The aperture is a leaf device inside the lens that controls how much light gets in.

Considerations

Full manual exposure control in its purest sense is a photo taken by a photographer based on his experience. He would set the aperture based on how much light there is on the subject, then set the shutter speed based on that. Essentially, this would be guesswork, but based on experience or experimentation. However, a tool such as a light meter can reduce the uncertainty.

Effects

A light meter, whether built into the camera or hand-held, is designed to tell photographers what light is available and how to get the best photo based on that. It has light sensitive cells, a pointer (or now, digital readout) and dials that can be moved based on the light sensitivity of the film and the conditions. It is essential to even some of the best photographers. Another method of manual exposure control would be to bracket photos. In other words, to take several photos of the same scene with different shutter and aperture combinations.

Benefits

Even the most sophisticated digital cameras usually have a full manual exposure control setting. This allows the photographer to play with the photo. For example, if auto exposure takes over, a waterfall will be sharp in the photo. If you want a soft, hazy feel to the photo, you can slow down the shutter speed and/or open the aperture beyond what the light meter tells you.