Module 4B: Utilizing the Exposure Triangle to Create Images

B. Utilizing the Exposure Triangle to Create Images 

 

 

The Sunny 16 Rule

The Sunny 16 Rule is less of a rule and more of a guide to help you quickly determine your f/stop and shutter speed in various outdoor lighting conditions. 

Every situation that you encounter has a measurable amount of light to work with, and with the help of a meter, it is easy to measure the exact amount of light for specific situations. The Sunny 16 Rule can help you learn to estimate the amount of light without the help of the meter.  

When working under daylight conditions only, there is a formula that makes calculating the exposure quite easy. We are looking for a starting exposure and this chart makes it simple to memorize. The formula is called the Sunny 16 Rule and looks like this:

 

Lighting Pattern / Starting Exposure
Sunny / f/16 @ 1/ISO
Partly Cloudy / f/11 @ 1/ISO
Overcast / f/8 @ 1/ISO
Heavy Overcast / f/5.6 @ 1/ISO

 

                                                                                                              

 For each of the lighting conditions, the f-stop is given. The shutter speed will be decided by the ISO that is being used.  

For example, if it’s a sunny day, and you are using 100 ISO, the starting exposure would be
f/16 at 1/125.
(1/125 is the closest shutter speed to 100 ISO.)

 

If you are using 400 ISO, the closest shutter speed will be 1/500, so your starting exposure would be f/16 at 1/500.

 

Once you have determined the starting exposure, then you can go through the equivalent exposure process we learned earlier, to determine the equivalent exposure you might wish to use, depending on the effect you want (see page 53).

 

Example 1

On a heavy overcast day using 400 ISO, the exposure would be 

f/5.6 @ 1/500.

You might want an increased DOF, so try

f/8 @ 1/250
or
f/11 @ 1/125
or
f/16 @ 1/60

 

All of these exposures will work, but f/16 will give you the most DOF. You can even go to f/22 at 1/30 but remember 1/30 may be too slow to hand-hold the camera without noticeable camera shake.

 

 

Example 2
This time we find ourselves on a sunny day with 100 ISO. The starting exposure will be
f/16 at 125. We want to freeze kids who are riding bicycles, so they appear sharp. 

f/11 @ 1/250
f/8 @ 1/500
or
f/5.6 @ 1/1000.

 

f/5.6 at 1/1000 will be the sharpest of the choices.