Now that we have become aware of the controls and options on our cameras, the next question arises: what camera settings do I use?
The Basic Exposure Formula #
The Basic Exposure Formula (or “B.E.F”) is a rule of thumb used for determining correct exposure for film or digital cameras without relying on a light meter. Commonly known as the Sunny 16 Rule, this rule states that when shooting an image in direct sunlight, the correct exposure will be:
- 1 / ISO @ F16
What does this mean exactly?
This means that when shooting outdoors in direct sunlight, you can set your aperture to f16 and adjust your shutter speed according to the ISO setting on your camera. Every film has an ISO number associated with it, while every digital camera has an ISO that needs to be set on the camera. The ISO references the film or sensor’s “speed” and how much light it needs to create an image. Every film/sensor needs just the right amount of light for a correctly exposed image. Too much light and film is overexposed (too bright). Too little and it is underexposed. (too dark.) The total amount of light hitting the film is determined by two settings on your camera, the aperture and the shutter speed.
If you are shooting with your camera set to ISO 100, then your exposure will be 1/100 @ F16, if you set it to ISO 1000, your exposure will be 1/1000 @ F16.
Now, because this is a beginner course, you are required to use what we call the Major Scale of Exposure Settings. Meaning, that instead of using 1/100 as a shutter speed, you have to choose the closest setting. In this case, you will choose either 1/125 or 1/60 as these are the full stop increments we are using in this class.
The Major Shutter Speed settings are:
30s, 15s, 8s, 2s, 1s, 1/2, 1/4, 1/8, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500, 1/1000, 1/2000, 1/4000 #
The Major Aperture settings are
f1, f1.4, f2, f2.8, f4, f5.6, f8, f11, f16, f22, f32 #
How to Use the Basic Exposure Formula for Better Control of your Images. #
|First, Set your ISO to 100:
|Next, set your camera to Manual Mode:
|Then, set your shutter speed and aperture to:
1/125 @ F16
This should yield a good, usable image.
*The BEF formula (1/ISO @ f/16) means that if you are using ISO 100 as your beginning setting for bright sun your exposure settings would be 1/100 @ f/16 (or equivalent); if you are using ISO 200 as your beginning setting your exposure would be 1/200 @ f/16 (or equivalent); if you are using ISO 400 as your beginning setting your exposure would be 1/400 @ f/16; and so on.
However, not all cameras have these shutter speeds, but all cameras do have 1/125, 1/250 and 1/500 etc… with ISO 100, since 1/125th is the closest shutter speed on many cameras, this shutter speed will be used, resulting in 1/125 @ f/16. For ISO 200, you would begin with 1/250 @ f16, ISO 400 would begin with 1/500 @ f/16 and so on.
Why shoot in Manual Mode and not the other modes? #
For Brightness Control. #
Manual Exposure gives you complete control over the brightness of your images. Most cameras have what is called a light meter inside of them that work to determine proper exposure. Today’s modern cameras have very intelligent light meters with different modes that will get you in the ballpark most of the time. However, there are instances where your light meter can and will give you an incorrect exposure, and you need to know how to expose your images yourself. It can be quite disappointing to realize (too late) that your camera has under or overexposed your image.
|Example of images exposed using an automatic mode (left) vs. shooting in Manual Mode (right)
|Because the image is lit from the rear, the camera is fooled into thinking the environment is brighter than it is. However, the photographer prefers to increase the exposure to see more of the fruit. This also causes the background to “blow out.”
Manual exposure also gives you the options to choose what you wish to emphasize in your image. The images below demonstrate two different exposures of the same subject. One image prioritizes the detail of the foreground, while the other prioritizes the detail of the sky in the background. In the image on the left, the camera chose to expose for the background, whereas the photographer chose to expose manually to increase the exposure and allow the foreground to be brighter.
For Aesthetic Control. #
You can control the overall feel of an image through exposure. These images look very different, even though they are of the same subject, taken at the same time, from the same angle. The only difference is exposure. This is a decision made by the photographer, using the manual exposure mode. Which do you prefer?
100 ISO: 1/125 @ F16
By exposing this at B.E.F., the detail of the sky is captured because it is lit by the sun. However, the front of the Mission is not lit by the sun and is therefore rendered much darker.
100 ISO: 1/30 @ F16
Here, the photographer chooses to emphasize the foreground by exposing +3 stops over B.E.F. This “washes out” the detail in the sky while making the building more visible.
The photography world is rife with opinions on which mode one should use when setting a camera. Should you set your camera to Manual mode or one of the automatic modes? As cameras become more sophisticated, the odds increase that you will get a good exposure using an automatic mode. But our objective is to get the correct exposure all the time and not leave it up to the camera.
As you become more familiar with exposure and your camera, you will eventually venture to use the other exposure modes, but you will know how they work and be able to adjust them as necessary.