There is no such thing as the perfect exposure.
The manufacturers might have you believe there is a perfect exposure for every shot. They invest a lot in their cameras and the programming. What should you look for when trying to produce a great shot? Is it about relying on camera auto-settings or is there something else?
The three pillars of exposure
You are probably aware of the three main controls for exposure…
- ISO – Controls how sensitive your camera image sensor is to light.
- Shutter speed – Controls how long your sensor is exposed to light.
- Aperture – controls how much light is allowed to reach the sensor.
These essential elements in exposure are inter-related. Each has an impact on the others. They relate to each other in two ways. As each varies it has an impact on the amount of light which reaches the sensor. And, as each varies, they have a special impact on the quality of the photograph…
- Low ISO gives a high quality result. High ISO introduces digital noise.
- Shutter speed – movement blur introduced at long exposure; movement frozen at short shutter speeds.
- Aperture – Wide aperture, shallow depth of field; small aperture gives a deep depth of field.
Controlling these elements to get a final exposure is essential. Highest ISO, widest aperture and a long shutter speed all together is likely to allow too much light into the camera in daylight. The shot will be over-exposed. The opposite is also true. A low ISO, tiny aperture and very fast shutter speed will allow very little light to enter the camera; result underexposure.
Exposure is about a balance. We must work at getting the three pillars to create the right light for the scene we envision. This is the key – creating the right light in the camera to make the scene come out the way we want. Yes, make the scene come out as we want. A photographer makes the picture that they want by controlling the exposure. A snapper captures the scene they see by relying on the camera to make the exposure for them. The difference between the photographer and the snapper is learning to control the camera.
Genius at work
By way of example I want to show you a short documentary video. Stanley Kubric made a period film, released in 1975, called Barry Lyndon. “Lyndon” was set in the 1750’s. It was a ground breaking work.
Kubric envisioned a cinematic experience which was as close to the way the eye would see life by the light of the time. He procured special lenses for his cameras and had them modified to work together. These lenses were F/0.7 Zeiss lenses made for NASA. They allowed the aperture to be open very wide – much wider than most modern lenses will go. As a result Kubric was able to use these fast lenses to film entire scenes only by candle light. This created an atmosphere which paralleled indoor light in the 1750’s. The costumes and set pieces were also of high quality. The overall effect is one of extreme authenticity.
A lot of pictures as dark as shots in this movie would be considered as under-exposed in the eyes of many photographers. Yet the gloom is the essence of the success of the shots. The exposure is correct for these scenes. Kubric went to extreme lengths to get the exposure he wanted. With the proper approach and control you can do the same in your photography.
The one consequence of shooting at such wide apertures is an extremely shallow depth of field. When you see the candlelit scenes you will see how much bokeh there is behind the heads of those in focus. What a gorgeous result.
This video is actually a commentary on “Barry Lyndon” the movie. I have started the video at the scene where the exposure and special lens set up is discussed. Despite this being a movie, the same internal camera conditions apply as in a DSLR. ISO, Shutter speed and aperture still have the same effect on each frame taken. Kubric showed true genius in marrying the camera and the lens into a unique synthesis that recreated the prevailing light conditions of the time. He literally controlled the exposure to emulate life in the 1750s. That is the genius of the man. It is also the supreme insight in photography.