Sunny 16 Rule Calculator

Enter your shutter speed, ISO, and light condition to calculate your exposure value, recommended settings, and depth-of-field hints using the Sunny 16 rule.

Created by Luis GonzalezLast updated: May 9, 2026

How to Use This Calculator

1
Enter Your Shutter Speed
Input the shutter speed in seconds (e.g., 0.01 for 1/100s). This is one side of the exposure triangle.
2
Specify Your ISO Setting
Enter the camera sensor's sensitivity (ISO). Common values include 100, 200, 400, 800, and 1600.
3
Select the Light Condition
Choose the prevailing light condition from options like 'Sunny 16', 'Slightly Overcast', or 'Sunset/Open Shade'.
4
Review Your Results
The calculator will display the exposure value (EV), recommended shutter speed, and ideal ISO for the given conditions.

Example Calculation

A photographer is shooting outdoors on a bright day, setting their shutter speed to 1/100s and ISO to 100. They want to know the exposure value for Sunny 16 conditions.

Shutter Speed (s)

0.01

ISO

100

Light Condition

sunny16

Results

10.3

Tips

Master the Exposure Triangle

The Sunny 16 rule is a shortcut, but true mastery comes from understanding the interplay of aperture, shutter speed, and ISO. Adjusting one impacts the others, allowing for creative control over depth of field, motion blur, and image noise.

Practice in Diverse Lighting

While the rule is 'Sunny 16,' practice applying its principles to other conditions. For instance, on a slightly overcast day, you might use f/11 (the 'Sunny 11' rule), or f/8 for overcast conditions ('Sunny 8').

Use Your Meter for Fine-Tuning

The Sunny 16 rule is an excellent starting point, but your camera's built-in light meter can help fine-tune exposure for tricky scenes, especially those with high contrast or unusual light sources. Always check your histogram for proper exposure.

Mastering Manual Exposure with the Sunny 16 Rule

The Sunny 16 Rule Calculator helps photographers quickly determine optimal exposure settings in various light conditions, from bright sun to open shade. This invaluable tool, which provides a baseline exposure value (EV) and recommended shutter speeds, enables precise manual control over your camera's settings. Whether you're aiming for a shallow depth of field at f/4 or freezing motion with a fast 1/1000s shutter, understanding these relationships is crucial for capturing well-exposed images without relying solely on a light meter, a skill still highly valued in 2025.

Mastering Exposure in Photography

Achieving a perfectly exposed photograph hinges on the delicate balance of the "exposure triangle": aperture, shutter speed, and ISO. Aperture controls the depth of field, shutter speed dictates motion blur, and ISO manages sensor sensitivity and image noise. The Sunny 16 rule provides a simple, yet effective, baseline for manual exposure settings, particularly useful when a light meter is unavailable or unreliable in challenging lighting. It offers a standardized starting point, allowing photographers to then make informed creative adjustments—for instance, intentionally slowing the shutter to create motion blur for a waterfall, or opening the aperture for a shallow depth of field in a portrait.

Unlocking Exposure Value with the Sunny 16 Principle

The Sunny 16 Rule Calculator helps translate real-world light conditions into actionable camera settings. It calculates the Exposure Value (EV) at ISO 100 (EV100) and then adjusts for your chosen ISO, providing a recommended shutter speed based on the classic rule.

The primary formula for EV100 is:

EV100 = log2((Aperture × Aperture) / Shutter Speed (s))

Where:

Aperture: The f-stop value (e.g., 16 for Sunny 16).
Shutter Speed (s): The duration the sensor is exposed to light, in seconds.
log2(): Logarithm base 2.

💡 To truly master exposure, understanding how your camera's sensor size impacts light gathering and depth of field is crucial. Our Sensor Size Comparison Calculator can help you grasp these fundamental differences.

Calculating Exposure for a Sunny Day Shot

Let's walk through an example using the Sunny 16 Rule Calculator. A photographer is outdoors on a bright, sunny day. They want to set their camera to an ISO of 100 and a shutter speed of 1/100th of a second (0.01s). They select the "Sunny 16" light condition, which implies an aperture of f/16.

Input Shutter Speed (s): 0.01
Input ISO: 100
Input Light Condition: Sunny 16 (which uses an aperture of f/16)

First, the calculator determines the EV100: EV100 = log2((16 × 16) / 0.01) EV100 = log2(256 / 0.01) EV100 = log2(25600) EV100 ≈ 14.65 (Note: My manual calculation earlier was slightly off, this one is more precise)

Then, it adjusts for the specific ISO if different from 100: EV at ISO 100 = 14.65 - log2(100 / 100) = 14.65 - 0 = 14.65

The Exposure Value (EV100) is approximately 14.65. The calculator would then recommend optimal shutter speeds or ISOs based on this EV, confirming that an f/16 aperture with a 1/100s shutter at ISO 100 is a classic correct exposure for bright sunlight.

💡 When reviewing your photos, the display quality matters. Our Screen Resolution to Physical Size Calculator can help you understand how image resolution translates to physical viewing size on different screens, ensuring your carefully crafted exposures are presented optimally.

How Professional Photographers Utilize Exposure Rules

Experienced photographers don't just blindly follow rules like Sunny 16; they use them as a robust starting point, then intuitively fine-tune based on their artistic vision and the nuances of the scene. Professionals often consider the concept of 'exposing to the right' (ETTR) in digital photography, which means setting exposure to capture as much light as possible without clipping highlights, thereby maximizing the dynamic range and minimizing noise in shadow areas during post-processing. This approach, which might involve slightly overexposing according to a meter and then correcting, is especially valuable for modern digital sensors. Understanding exposure value allows them to quickly adapt to changing light, predict how different settings will affect the final image, and make rapid, informed decisions, such as knowing that an EV of 15 is typical for bright sun, while an EV of 8 might be for a dimly lit indoor scene.

Frequently Asked Questions

What is the Sunny 16 Rule in photography?

The Sunny 16 Rule is a mnemonic for estimating correct daylight exposures without a light meter. It states that on a sunny day, with an aperture of f/16, the correct shutter speed will be the reciprocal of the ISO speed. For example, if your ISO is 100, your shutter speed should be 1/100th of a second at f/16. This rule provides a reliable baseline for manual exposure settings in various outdoor lighting conditions, making it a fundamental skill for photographers.

What is Exposure Value (EV) in photography?

Exposure Value (EV) is a system that combines aperture and shutter speed into a single number representing a specific level of photographic exposure. An EV of 0, for instance, typically corresponds to an exposure of 1 second at f/1.0 with ISO 100. Each step up in EV represents a doubling of light, meaning a one-stop increase in exposure. EV helps photographers compare different exposure settings that result in the same overall brightness.

How does the light condition affect the aperture in the Sunny 16 Rule?

The 'Sunny 16' rule is a baseline, but the aperture adjusts based on the light condition. For slightly overcast skies, the rule becomes 'Sunny 11' (f/11); for overcast days, 'Sunny 8' (f/8); and for heavy overcast or open shade, 'Sunny 5.6' (f/5.6) or 'Sunny 4' (f/4) might be appropriate. These adjustments compensate for the reduced light intensity, maintaining the correct exposure relative to your ISO and shutter speed.

Why is the reciprocal shutter speed important?

The reciprocal shutter speed is a key component of the Sunny 16 rule, where the shutter speed is set to approximately 1/ISO. This means if your ISO is 200, your shutter speed will be around 1/200th of a second. This direct relationship simplifies exposure calculations in bright conditions and helps maintain a balance that typically yields well-exposed images. It's a quick way to establish a baseline exposure without needing complex calculations or a light meter.