Sunny 16 means using an F16 F-Stop on a bright and sunny day instead of using your camera’s built-in light meter or an external light meter. This idea came about when cameras didn’t not have built-in light meters or the light meters that were available cold not be depending upon for accurate light readings. Sunny 16 was developed as a rule of thumb to approximate proper exposure on a sunny day. Sometimes the “Sunny 16” rule is referred to as the “Rule of 16.”
What are the Sunny 16 Rule/Rule of 16 Camera Settings?
To use the Sunny 16 rule set your F-Stop to 16 and your shutter speed to the inverse of your film speed. This means that if your film speed is 400 then you would use a 1/400th of a second shutter speed. Remember that your camera will only show the “400” on your shutter speed indicator, not the full fraction. Don’t forget that if you are using a long lens, such as a 300mm lens, you’ll need a shutter speed of 1/300 or faster in order to reduce your chances of camera shake during exposure. This means that with a long lens your film speed choices are limited if you use the Sunny 16 rule.
When Can I Use the Sunny 16 Rule?
You can use the Sunny 16 rule on a day when the sun is shining brightly and not hidden by clouds. The Sunny 16 rule should also be used only when the sun is high enough in the sky that the light color temperature is close to full daylight. In other words, use Sunny 16 anytime 2 hours after sunrise until 2 hours before sunset. Of course, these times will vary somewhat depending on your location and time of year but they should get you in the general needed timeframe.
If you attempt to use the Rule of 16 (Sunny 16) outside of the main part of the day, say at the blue hour, the strength of the sun’s light will not be enough to give you a solid exposure. However, occasional clouds and other slight light modifications should not render photos unusable even though they will alter the resulting exposure somewhat.
Does Sunny 16 Work for Other Situations?
No, Sunny 16 does not work in other lighting situations. However, there are other rules of thumb based off of sunny 16 that can work in other lighting conditions. In general, as the light fades, lower the F-Stop (open the aperture) while keeping the other numbers the same.
Adapting Sunny 16 for Other Lighting Conditions: (examples shown at ISO 400 for consistency)
Very Cloudy Day (no patches of bright sunshine)
Film Speed - 400
Aperture/F-Stop - 8
Shutter Speed - 1/400
Shade
Film Speed - 400
Aperture/F-Stop - 4
Shutter Speed - 1/400
Backlighting
Note that if you want to achieve backlighting you would base your numbers on the light behind the subject rather than the light falling on the subject. For example, use the traditional Sunny 16 rule if your subject is in shade but the background is in bright sunlight (film speed 400, F-Stop 16, Shutter 1/400). This allows the photo to be exposed for the light behind the subject and render the subject itself dark.
Examples of the Sunny 16 Rule and Rule of 16 Settings
| Film Speed | Aperture/F-Stop | Shutter Speed |
| 100 | 16 | 1/100 |
| 200 | 16 | 1/200 |
| 300 | 16 | 1/300 |
| 400 | 16 | 1/400 |
| 800 | 16 | 1/800 |
