What is Sunny 16 rule?

Susan Fernandez December 12 2021

What does this rule mean?

This is a rule of thumb that photographers use to help them determine the correct exposure settings when shooting in bright sunlight. The rule states that if the photographer sets their camera to an aperture of f/16 and ISO 100, they can be assured that their photograph will be correctly exposed.

The sunny 16 rule is based on the fact that in bright sunlight, the human eye can see details up to 16 shades of light grey. By setting the camera to an aperture of f/16, the photographer ensures that all 16 shades will be captured in their photograph. Additionally, by setting the ISO to 100, the photographer minimizes any noise or graininess that might appear in the image.

While this rule is a great starting point for photographing in bright sunlight, it is not always accurate. Depending on the specific lighting conditions, the photographer may need to adjust their exposure settings accordingly. For example, if the subject is backlit, they may need to increase the aperture to f/22 or f/32 in order to capture all of the detail in the photograph.

The sunny 16 rule is a great starting point for photographing in bright sunlight. By setting the camera to an aperture of f/16 and ISO 100, the photographer can be assured that their photograph will be correctly exposed. However, depending on the specific lighting conditions, they may need to adjust their exposure settings accordingly. For example, if the subject is backlit, they may need to increase the aperture to f/22 or f/32.

Aperture and Shutter change

While you are dealing with changes of shutter and aperture, let`s dive into it deeper. Aperture is the hole inside your lens that light travels through. The size of the aperture determines how much light will reach the sensor. When you increase or decrease the aperture size, you are also changing the depth of field in your photograph. A shallow depth of field will have a small area in focus, while a deep depth of field will have a large area in focus.

The shutter speed is the length of time that the shutter is open and allows light to reach the sensor. When you increase or decrease the shutter speed, you are also changing the amount of motion blur in your photograph. A fast shutter speed will freeze any motion in the photograph, while a slow shutter speed will create a blurred effect.

So-called changes in shutter and aperture can be tricky. You might want to control motion blur or the depth of field. It all depends on your creative desires and what you are aiming to photograph. As always, experiment and find what settings work best for you.

Stop difference and changes

Aperture also affects the image by controlling the amount of light that passes through the lens. Aperture is measured in f-stops, with each number representing a halving or doubling of the light allowed to pass through the lens.

Shutter speed, on the other hand, determines how long the sensor is exposed to light. It is usually measured in seconds, or fractions of a second. Together, aperture and shutter speed control two aspects of exposure: how much light reaches the sensor and how long the sensor is exposed to that light.

When you change one of these settings, you are indirectly changing the other setting as well. For example, if you increase the shutter speed, you will need to decrease the aperture size to maintain the same exposure. Or, if you want to keep the shutter speed and aperture constant, you will need to increase the ISO setting.

It is important to remember that these settings are not set in stone. You can change them to fit your creative desires or the specific situation that you are photographing. Experiment and find what works best for you.

How does the Sunny 16 rule look in action?

Now that we have a basic understanding of the Sunny 16 rule, let's take a look at how it works in action. In the photograph, the subject is facing the sun and the sky is very bright. If we were to follow the Sunny 16 rule, we would set our aperture to f/16 and ISO to 100. However, because the sun is so bright, our photograph would be overexposed.

To compensate for this, we need to decrease the aperture size or increase the ISO setting. In this case, we decreased the aperture size to f/8 and increased the ISO setting to 400. This allowed us to maintain the correct exposure while still keeping the sun in the frame.

What about camera settings?

When it comes to camera settings, there are a few things you need to keep in mind. First, your camera will likely have two different shutter speed settings: one for still subjects and one for moving subjects.

Second, your camera will also have two different aperture settings: one for wide-angle shots and one for telephoto shots. Third, your camera may have a landscape or portrait mode that adjusts the aperture and shutter speed automatically. Fourth, your camera may also have a full manual mode where you can manually control the aperture, shutter speed, and ISO setting.

Camera settings: 1/1000 sec at f8, ISO400

This is the correct exposure according to the Sunny 16 rule. However, if we were to focus on our subject's feet in this photograph, the background would be out of focus due to a shallow depth of field created by the aperture size.

Camera settings: 1/2000 sec at f8, ISO100

In such a photograph, it appears as though our subject is walking away from us into an infinitely deep tunnel. This effect is created by using a long shutter speed to blur the motion of our subject. If we were to follow the Sunny 16 rule chart, we would use a shutter speed of 1/2000 sec. However, because our subject is moving, a faster shutter speed is needed to freeze their motion.

Camera settings: 5 seconds at f8, ISO100

In case you have such a final photograph, we used a very slow shutter speed of 5 seconds to create a blurred effect. This can be used to show the motion of people or cars in a cityscape photograph. If we were to follow the Sunny 16 rule, we would use a shutter speed of 1/30 sec or less. However, because our subject is stationary, we can use a slower shutter speed to create this effect.

When should you use the Sunny 16 rule?

Now that we have an understanding of how the Sunny 16 rule photography works, let's take a look at when it can be used. First, if you are photographing people or objects that are stationary during the day, the Sunny 16 rule is your best bet for getting proper exposure.

Second, if your scene primarily has one predominant light source (e.g., sun) and there aren't any bright highlights in the scene (e.g., specular reflections), you will want to stick with using the Sunny 16 rule as well. If your scene does have other bright elements within it, then you may need to adjust settings so that those brightest elements don't overexpose.

Finally, the Sunny 16 rule is best used in bright daylight conditions. This means that if your scene is lit by natural light or indoor lighting (e.g., fluorescent lights), then you will want to stick with using an aperture value of f/8 and shutter speeds less than 1/125 second.

If any of these situations apply to you, then you should probably stick with using the Sunny 16 rule for proper exposure:

  • You are photographing stationary subjects during the day
  • Your scene primarily has one dominant light source and there aren't any highlights within it
  • Your scene is lit by natural light or indoor lighting

Exposure, overexposure, and underexposure

Now that we have a general understanding of the Sunny 16 rule, let's take a look at what happens when it is not followed. When you underexpose a photograph, the darker areas of the image will become even darker and the brighter areas will become even brighter. This can lead to an image that appears washed out or void of color.

When you overexpose a photograph, the darker areas will become lighter and the brighter areas remain unchanged. This can lead to blown highlights in your image. Overexposed photos often appear very bright at first glance, but upon closer inspection detail is lost due to these blown highlights.

Finally, if you don't follow the Sunny 16 rule chart, then your image may suffer from both underexposure and overexposure simultaneously. When this occurs, it will seem like there are large chunks of pure white (overexposed) and black (underexposed) within your photo.

Experience shows that this type of exposure is typically caused by using an incorrect meter mode (e.g., spot metering) on your camera or by having a very high contrast scene (e.g., backlit).

Bottom line

The Sunny 16 rule photography is based on the idea that you can use an aperture of f/16 and shutter speeds that correspond to your ISO to get proper exposure in daylight conditions. While the Sunny 16 rule isn't perfect, it's usually pretty close.

However, there are many situations where you will not be able to follow this method for getting proper exposure, so it is always best to do some post-processing work on your images before sharing them with others.

Taking photos in natural lighting conditions is one of the most popular ways of taking pictures these days, so learning how best to expose your images using the Sunny 16 rule is a must for any digital photographer.