Considering how simple it is, how is it that every post I read about Sunny 16 confuses me? Well, time for me to write my own confusing post about it, to help myself (maybe? hopefully?) remember it better.

I don’t care about the hows and whys behind its working. I can investigate that later. Right now, I’m looking for how to apply it. Since I use the Nikon D40, I’ll reference it, but I’ll bet other DSLR cameras work exactly the same anywhere I mention the Nikon D40. (Also note, with the Nikon D40, I have the camera’s mode dial set to M, for “Manual” mode.)

Why Sunny 16?

The common question to ask by anyone new to a DSLR after moving up from a point-and-shoot will likely be, “Why bother trying to remember some complex game of numbers when the camera does the job for me on Auto?” It’s true, you can use the camera’s Auto setting and get images much better quality than that old point-and-shoot was able to produce. However, the Auto setting isn’t going to always get the exposure right.

Consider the following photographs. The photograph on the left was taken with the Nikon D40 in “Auto” mode. The photograph on the right was taken with the camera in “Manual” mode, with care taken to set the values correctly for Sunny 16.

The “Auto” photograph’s colors are washed out in comparison (due to incorrect exposure) to the “Manual” photograph’s vibrant colors.

Next question: If I shoot in RAW format, I can adjust the exposure and other settings after taking the photo. Why not just do that? The answer here is another question: Why not get the exposure right the first time? Then you don’t have to manually edit the exposure on various images to increase it on some and decrease it on others.

Let’s look into the camera’s available settings and how Sunny 16 applies to to them.

Aperture

Let’s see if I know aperture by now. This is how much light goes in the lens. The Nikon D40 shows me a graphic to help me understand this. At ƒ/22, it’s a small hole that lets very little light in. At ƒ/4, it’s a huge opening that lets a lot of light in.

For a low depth-of-field, a number such as ƒ/4 is used. This lets a lot of light in, and the background falls out of focus. This needs a faster shutter speed so it doesn’t let so much light in that it overexposes the photo.

For a high depth-of-field, a number such as ƒ/22 is used. This lets little light in, and the background remains in focus. This needs a slower shuter speed so it doesn’t let in so little light that it underexposes the photo.

Shutter Speed

The longer the shutter is open, the more time that passes while a photograph is being taken. I understand this. If the shutter speed is 30 seconds (30″ on the Nikon D40), light will be entering the camera for 30 seconds. If the shutter speed is 1/100 (100 on the Nikon D40), then light will enter the camera for 1/100th of a second.

If the shutter speed is very fast, the aperture must open enough to let in enough light (or the photo will be too dark). If the shutter speed is very slow (open for a long time), the aperture must be open little so the photo doesn’t let in too much light (or the photo will be too bright).

ISO

My understanding of ISO is very weak. It’s the camera’s sensitivity to light. The aperture controls the amount of light that can reach the sensor and the shutter speeds controls how long the light enters. The ISO is how sensitive the camera is to the light that’s coming in.

Use a low ISO in sunlight. For indoors, a lower ISO is more sensitive to the light that enters, so you can get a brighter image without slowing the shutter or openning the aperture, but at the same time you get more noise. After all, the light entering the camera stays the same. The camera simply is more sensitive, so you get a brighter image at the expensive of noise being introduced.

Applying Sunny 16

Now to put it all together. Consider a bright, sunny day, no clouds, and shadows are black with sharp edges. To get the right exposure (not to bright, not too dark), you want the following camera settings: aperture ƒ/16, shutter speed 1/ISO.

What, what’s with 1/ISO? That means the shutter speed should be 1/Xth of a second where X is the ISO value. If the ISO is 100, then you want a speed of 1/100 at ƒ/16. If the ISO is 400, you want a speed of 1/400 at ƒ/16. Remember, this only applies to a sunny day with those strong shadows!

But wait! What about if we want a shallow depth of field? We want to use ƒ/4 instead! This introduced a problem. See, as noted above, this lets in more light, so we need to speed up the shutter to let in light for less time.

This is where we reach the confusing part, and shouldn’t be attempted by anyone who (like myself) doesn’t understand where the concept of “full ƒ stops” comes from or what it means.

We’ll try to continue, though. Let’s assume the aperture is measured in “ƒ stops”, and these stops include: ƒ/16, ƒ/11, ƒ/8, ƒ/5.6, ƒ/4. You don’t have to try remembering these numbers. They’re all on the camera. (The the Nikon D40 moves in thirds of an ƒ stop, but we’ll address that later.)

Now, how do we get from an aperture of ƒ/16 to ƒ/4 for that narrow depth-of-field on a sunny day? Looking at the list of ƒ numbers above (which you won’t need to memorize), it’s ƒ/16 to ƒ/11 to ƒ/8 to ƒ/5.6 to ƒ/4. That’s four movements.

Okay, we know that ƒ/16 to ƒ/4 is four full ƒ stops. What do we do with that number? We want to apply that value to the shutter speed. If we want to slow down the shutter, we halve the shutter speed that number of times. If we want to speed up the shutter, we double it by that number of times.

You don’t have to remember this math, either, but let’s look at what’s happening. We’ll begin with Sunny 16:

ISO 100. Shutter speed 100. ƒ/16.

Now, we’re dropping ƒ/16 down four full ƒ stops to ƒ/4. This means we need a faster shutter speed, so we’ll double the shutter speed four times.

ISO 100. Shutter speed (((100*2)*2)*2)*2. ƒ/4.

ISO 100. Shutter speed ((200*2)*2)*2. ƒ/4.

ISO 100. Shutter speed (400*2)*2. ƒ/4.

ISO 100. Shutter speed 800*2. ƒ/4.

ISO 100. Shutter speed 1600. ƒ/4.

But what if you’re shooting at ISO 200? Remember, at ƒ/16, the shutter speed is 1/ISO, which works out to 1/200th of a second.

ISO 200. Shutter speed 200. ƒ/16.

ISO 200. Shutter speed (((200*2)*2)*2)*2. ƒ/4.

ISO 200. Shutter speed ((400*2)*2)*2. ƒ/4.

ISO 200. Shutter speed (800*2)*2. ƒ/4.

ISO 200. Shutter speed 1600*2. ƒ/4.

ISO 200. Shutter speed 3200. ƒ/4.

I said before that you won’t need to memorize the ƒ stop number or the math. The Nikon D40 (and probably any other DSLR camera) does all the work for you. When you adjust the dial for the aperture (which moves in thirds of an ƒ stop on the Nikon D40), you need only adjust the shutter speed the same amount on the dial.

Consider the following:

ISO 100. Shutter speed 100. ƒ/16.

With the Nikon D40, I’ll adjust the aperture to be ƒ/11. This is the next full stop down. As I turn the dial left (while holding the top button to let the camera know I want to adjust the aperture), the ƒ stop value moves to ƒ/14, then ƒ/13, then ƒ/11. Again, the Nikon D40 moves in thirds of an ƒ stop, so it takes three notches on the dial to move one full ƒ stop.

Now, the shutter speed needs to be doubled one time, because we moved one full ƒ stop value. This means we want it to move from 1/100 to 1/200. Since the aperture moved the dial left, I’ll move it to the right for shutter speed. Starting with 1/100, three notches to the left moves it to 1/125, then 1/160, then 1/200. The shutter speed has also moved in thirds.

The Easy Way

All I have to remember is how to start out with Sunny 16. From there, I need only move the shutter and aperture the same number of notches in opposite directions to keep the exposure happy.

Sunless 16

Although I have experimented with it yet, I’ve read that a different starting value must be used when it’s not completely sunny. I’ve read that you can judge which starting value to use based on shadows. I assume the shutter speed begins the same as the ISO, and only the starting ƒ value differs.

If it’s sunny out, there will be strong, sharp-edged shadows, and you want to start with ƒ/16.

If it’s partly cloudy out, there will be soft-edged shadows, and you want to start with ƒ/11.

If it’s very cloudy out, there will be hardly-visible shadows, and you want to start with ƒ/8.

If it’s completely cloudy out, there will be no visible shadows (everything is shadow), and you want to start with ƒ/5.6.

Oh yeah, and one other thing: Sunny 16 only applies to when the sun is up. This means after sunrise and before sunset. In practice, this tends to be about 10:00 AM through 5:00 PM, but longer and shorter days, and where one lives, will affect this range.

Hm, I need to write a “Sunny 16 Simple Version” which removes all the complex parts from this post.