Sunny 16 rule

About a month ago I won a Red Army Camera ( at a photo competition. As it happens, the Red Army Camera is a Custom made vintage Film Camera. Some Time later I was on a trip to Vietnam where I noticed, that I didn't bring my light meter. That's the moment I remembered that although you may think that no two situations are alike, the fact is that there are a few constants that you can rely on. The sun is One of those things which gives you a good starting point.USKu can count on that this is one of the consistent points. Of course there are things that affect the sun’s output like time of day, haze, fog and clouds, but on a bright sunny day the light output is very consistent and knowing the camera settings for this condition will give you a guideline to make adjustments.

This is the old “sunny 16″ rule.

Simply put, you can count on the fact, that on a bright sunny day, if you set your camera on f/16 and set the shutter speed to the reciprocal of the ISO speed, you are in a save range to get a decent exposed image. So if you are set to ISO 200, then set your shutter speed to 1/200th. If you want a faster shutter speed then increase the shutter speed and set the ISO to match. For example, if you want to shoot at 1/400th of a second, set the ISO to 400.

To compensate for other conditions, simply adjust the f-stop to a more open or closed setting like f/11, f/8 etc. adjusting as needed. A good chart of recommended settings is in the following table:

Aperture Lighting Conditions Shadow Detail
f/22 Snow/Sand Dark with sharp edges
f/16 Sunny Distinct
f/11 Slight Overcast Soft around edges
f/8 Overcast Barely visible
f/5.6 Heavy Overcast No shadows
f/4 Open Shade/Sunset No shadows
Add One Stop Backlighting n/a


You See, that The Sunny 16 rule can also help to determine aperture and shutter speed settings when conditions are not typical sunny days.


Set Your F-Number
Set your f-number to f/16. If you don’t have strong sunlight, use the next list to determine your starting f-number.

Set Your Shutter Speed
Take note of your ISO or film speed (let’s call it “X”). Now set your shutter speed to 1/X. So at ISO 400, you’d use a shutter speed of 1/400 seconds.

Adjust With Reciprocals
You may want to use different shutter speeds or f-numbers. You can adjust one as long as you adjust the other accordingly. Opening up by one full f-number requires cutting your shutter speed in half (and visa versa).