Using the Sunny 16 Rule for Correct Exposure

sunny 16 rule

Photography is fun, but can get frustrating if your photos don’t end up as you intended. There are several things to take into account before you snap a picture: subject, light, composition, and a myriad of settings on your camera. One of the toughest factors for a photographer to deal with would have to be exposure; this is where The Sunny 16 Rule comes in handy. The rule provides a method of estimating the correct aperture and shutter speed settings for your camera based on the current lighting conditions.

What about a light meter?

Off-camera light meters are great, but 1) not all of us have one, 2) it’s not always convenient to pull one out every time you take a picture, and 3) they’re not the best for difficult subjects. The Sunny 16 Rules compensates for very light or very dark subjects very well. Why? Because the Sunny 16 Rule is based on the incident light hitting your subject rather than the reflected light bouncing off of your subject. The light meter built into all digital cameras works based on reflected light, but can’t always by relied upon. If you’ve ever tried to take a picture of the sunset and your photo ended up grossly underexposed, this is because the reflected-light meter in your camera overcompensated for the bright sun. Incident-light meters do exist, but they must be placed at the location of the subject facing the camera, which isn’t always possible (e.g. landscape photography). For more info on incident and reflected light, click here, but enough science for now, let’s get to the good stuff…

Using the Sunny 16 Rule

The Sunny 16 Rule is actually quite simple. Assuming a baseline lighting condition of a sunny day, your camera should be set to:  an ISO of 100, an aperture of f/16, and a shutter speed of 1/100 (or 1/125 if your camera  does not have a 1/100 shutter speed). That’s it.

You’re probably saying, “This rule won’t work for me because I live in London where it’s foggy most of the time. Thanks for nothing, buddy!” Don’t fret, my friends, the Sunny 16 Rule works for other lighting conditions, as well! Just use the settings in this simple table while keeping your ISO at 100:

Aperture Lighting Conditions Shadow Detail
 f/22 Snow/Sand Dark with sharp edges
 f/16 Sunny Distinct
 f/11 Slightly Overcast Soft edges
 f/8 Overcast Barely visible
 f/5.6 Heavily Overcast None
 f/4 Open Shade/Sunset None

The Sunny 16 Rule isn’t the end all, be all answer to getting the right exposure; it’s more of a guideline. If you find that your photo is still a little too light or too dark after applying the Sunny 16 Rule, try adjusting the aperture a couple of stops or bumping the shutter speed until it’s just right!