The Sunny 16 Rule: What It Is and How to Use It?

Techniques to perfect photography seem to be evolving, especially as cameras get more sophisticated. However, there are still some tried and tested photography approaches that are still useful in helping you become an even better photographer. The Sunny 16 rule may be considered to be an old school approach, but it is still something which is essential to know. In this article, you will learn all about what the Sunny 16 rule is and how you use it in photography.

Sunny 16 Rule: what exactly is it?

As the name indicates, this technique for metering ensures that you have the correct exposure on clear and sunny days without actually using the camera’s meter. Essentially, this rule states that if you are shooting on a clear and sunny day and the aperture is at f/16, whatever ISO you choose, the shutter speed should be the reciprocal value to it. In other words, if you have an ISO 200 with an f/16 aperture, your shutter speed should be 1/200 sec. If you use ISO 400 your shutter speed should be 1/400 sec and so on.

Sounds straightforward, right? Well, this rule can get more complicated as you use different aperture values as you can see in the chart below. For example, say you are now using an aperture of f/11 instead of f/16. You have increased the amount of light that will enter the camera by +1 stop (as f/11 is a wider aperture than f/16). To compensate for this you need also reduce either the ISO or shutter speed by -1 stop. In other words, you will need to either increase your shutter speed to 1/400th sec or reduce your ISO to 100. For now, you can just use a chart below to help you (ISO to remain constant at 200).

Aperture	Stop difference	Shutter speed	Stop difference
f/22	-1	1/100 sec	+1
f/16	0	1/200 sec	0
f/11	+1	1/400 sec	-1
f/8	+2	1/800 sec	-2
f/5.6	+3	1/1600 sec	-3
f/4	+4	1/3200 sec	-4
f/2.8	+5	1/6400 sec	-5

Why do you need the Sunny 16 rule?

There are several reasons why this is still an essential approach in photography. For one thing, if you are new to photography it gives you an easy to remember set of parameters to get you close to the correct exposure in different conditions. Rather than having to remember ISO and shutter speed, you can just memorize the different apertures for different conditions.

But additionally, it helps you see if the camera has the correct exposure or if there is a constant over/underexposure. Some cameras tend to underexpose a little bit, so this approach can help you test the camera.

Another benefit of this approach is that the camera’s metering system is based on reflected light rather than the incident light. What this means is that the camera determines how bright a scene is based on the light reflected off of your subject into the camera. This isn’t always accurate as the camera’s metering system can be tricked. For example, try taking a photo of someone dressed in white standing in front of a white background and you’ll notice that your image comes out darker than you expected. This is because your camera thinks all that white is brightness underexposes.

The Sunny 16 rule, on the other hand, is based on the brightness of the light source. That’s why it’s essential to learn it and use it when you need it.

How to use the Sunny 16 rule

The basis of this rule is consistency in light. But different weather conditions can impact the light in a scene, meaning that you will need to change the aperture setting to get the correct exposure in these various types of weather. For instance, let’s say you are photographing when it’s heavily overcast. This means there is less light than on a clear sunny day. Now you need to ensure more light gets into the camera. Using the basis of this rule you can keep your ISO and shutter speed the same as before (i.e. ISO 200, 1/200 sec shutter speed) and simply open your aperture to f/5.6. This will get you close to the correct exposure.

Here is a closer look at these variations in the Sunny 16 rule for different conditions:

Sunset	Heavily overcast	Overcast	Slightly overcast	Clear & sunny	Snow/Sand
f/4	f/5.6	f/8	f/11	f/16	f/22

Use it as a starting point

These type of “cheats” are great when you are starting out and need some help. But nothing beats relying on instinct and experience to choose the right settings. Because one of key attributes of photographers is being able to share their vision in their photos. Sometimes that means breaking the rules sometimes the rules actually can hinder you. So use the sunny 16 rule as a good starting point. But learn how to increase or decrease your ISO, shutter speed and aperture to get the result that you want.

There are plenty of people that will tell you that the Sunny 16 rule is outdated and unnecessary. However, this is just another tool that you can use to take the best pictures possible. There is a reason why this is still an approach that photographers use today.

Photo credits: Kav Dadfar – All rights reserved. No usage without permission.