A lot of photographers get a little dizzy thinking about Manual mode as though that little M that makes your photographs too bright or too dark stands for Master.

It doesn’t; most professional photographers, myself included, use Aperture-priority mode 70% of the time. However, for the other 30%, I’ll probably be using Manual mode.

I’m going to teach you how to properly use Manual Mode so that you can understand when and why to use it; then reset the camera to Aperture-priority mode again!

Manual mode switches off the automatic exposure control that camera designers spent years developing. Before, you had to guess the exposure, aided only by a rough guide on the camera body itself;

The Sunny 16 Rule helps photographers to guess the exposure. It works on the premise that direct sunlight on a sunny day has a fairly constant brightness value.

Dawn, dusk, clouds and mist will all reduce the amount of light, but any time two hours after sunrise and two hours before sunset with clear skies, this ‘rule’ will work well.

Therefore, by setting your Aperture to f16, the only thing affecting your Shutter Speed is your camera’s ISO Sensitivity. (Read our Exposure Fundamentals if this doesn’t make sense).

Set your Aperture to f16 and your Shutter Speed will be an inverse of your (nearest) ISO Sensitivity;

Aperture = f16

Shutter speed = 1/ISO Sensitivity

Example: If I’m photographing a sunlit landscape on a cloudless day with my Hasselblad 500cm, which doesn’t have a light meter to automatically set the exposure, I can guess the exposure using the Sunny 16 Rule.

[tabs][tab title=”ISO 100″]

Aperture = f16

ISO Sensitivity = 100

Shutter speed = 1/100s


[tab title=”ISO 200″]Aperture = f16

ISO Sensitivity = 200

Shutter speed = 1/200s[/tab]

[tab title=”ISO 400″]Aperture = f16

ISO Sensitivity = 400

Shutter speed = 1/400s[/tab]

[tab title=”ISO 800″]Aperture = f16

ISO Sensitivity = 800

Shutter speed = 1/800s[/tab][/tabs]
With me so far? You can have a look at our Exposure Fundamentals for more information; otherwise, let’s move on.

The next thing to consider is that if the amount of light on our beautiful sunny day is fairly constant, we can give the amount of light a number; an Exposure Value (EV).

Photographers have already done this of course, and you can Google ‘Exposure Values’ to find out more about them if you want. This is just a stepping stone for us though because you’re unlikely to come across Exposure Values in your photography.

If I tell you that the Exposure Value of direct sunlight on a typical subject is roughly EV15 it is only so that you can appreciate that is a fairly constant amount of light.

Now for the important part; this means that if you double the amount of time that the camera shutter is open for (and light is coming into the camera), you need to halve the size of the hole through which the light enters to capture the same amount of light. And vice versa.

So assuming that the ISO Sensitivity is also constant (let’s say it’s ISO 100) have a look what happens when you change the Aperture – the f-numbers;

[tabs][tab title=”f16″]

Shutter speed = 1/125s

(Yes, the Sunny 16 Rule requires 1/100s but 1/125s gets us closer to EV15 (sunlight on a typical scene) at f16)
[/tab][tab title=”f11″]

Shutter speed = 1/250s

(Wondering where the f-numbers come from? Click here for some mathematics that explains it.)[/tab]
[tab title=”f8″]

Shutter speed = 1/500s

(Wondering where the f-numbers come from? Click here for some mathematics that explains it.)[/tab]
[tab title=”f5.6″]

Shutter speed = 1/1000s

(Wondering where the f-numbers come from? Click here for some mathematics that explains it.)[/tab]
[tab title=”f4″]

Shutter speed = 1/2000s

(Wondering where the f-numbers come from? Click here for some mathematics that explains it.)[/tab]
[tab title=”f2.8″]

Shutter speed = 1/4000s

(Wondering where the f-numbers come from? Click here for some mathematics that explains it.)

So if you know one set of exposure settings for the light you’re in (e.g. EV15: ISO100, f16, 1/125s), you can adjust your Shutter Speed or Aperture combination and still get the same exposure. Useful; we’re getting control.

You don’t need to learn Exposure Values (EV) because you will learn these Shutter Speed/ Aperture/ ISO Sensitivity combinations with practice. Just bear with me for a little more about Exposure Values then we can move on from them.

A cloudy, overcast day will reduce the amount of light reaching us; and so the Exposure Value of our scene will be a lower number; EV12, for example.

The difference between the main Aperture numbers (f2.8, f4, f5.6, f8, f11, f16) and Shutter Speeds (1/30s, 1/60s, 1/125s, 1/250s, 1/500s, 1/1000s) are called exposure Stops.

Helpfully, they correspond to the Exposure Values. Imagine that a naughty cloud reduces the amount of light on our subject from EV15 to EV14. All we need to do to achieve the same Exposure is to change our Aperture from f16 to f11 (the hole is bigger so lets in more light); or our Shutter Speed from 1/125s to 1/60s (the hole is open for longer so lets in more light); or our ISO Sensitivity from 100 to 200 (the camera receives less light but we double whatever light we do receive). Stop now and have a think about this.

Good. So with Manual Mode, all we’re doing is taking full control over these three variables (Aperture, Shutter Speed, ISO Sensitivity) based on the amount of light on our subject.

Photographers used to use hand-held Exposure meters to measure the amount of light of their subject. Using the EV value, they could set the appropriate Aperture, Shutter Speed and ISO combination for the exposure they wanted.

You don’t need to think about this. Your camera has a built-in meter, and with a digital camera, instant display of your pictures.

How to Set Your Camera in Manual Mode

We always want our ISO Sensitivity to be at its base setting; usually 100 and occasionally 200. This gives us the best image quality. We might have to compromise, but for now, set your ISO to 100.

We’ve been dealing with the Sunny 16 Rule and an Aperture of f16. Actually, your lens is probably sharper between f4 and f8, so let’s set the lens to f8. (You can check out the performance and sharpest Aperture of your lenses at Photozone, DXO Mark and SLR Gear)

With your lens set to an Aperture of f11, effectively a hole twice as big as f16, you will only need half the time to build up the same exposure. Your Shutter Speed will therefore be half of 1/125s; so 1/250s.

Now take a photograph of your subject. How did it come out? Unless it’s lit by direct sunlight as per the Sunny 16 Rule, your photo will probably be too light (over-exposed) or too dark (under-exposed).

Let’s suppose that we’re in the shade, and the photograph is too dark. We can amplify the small amount of light that we do have by increasing the ISO Sensitivity; but higher ISOs reduce image quality. Instead, we can let more light into the camera.

We can do this by increasing the physical size of the Aperture (choosing smaller numbers!) or the length of time that the Aperture is open for (1/30s, 1/60s etc. – which look like smaller numbers but aren’t because they’re inversed – 1/number).

Let’s suppose that we change the Aperture to f5.6, letting twice as much light into the camera. Our photograph will be brighter; but we haven’t achieved the perfect exposure yet.

Next, we set the Shutter Speed to 1/60s, letting twice as much light again into the camera. This looks just right.

With a digital camera, I aim to have Diffused Reflections on white surfaces such as walls and paper almost clipped/ blown out, but not quite. You can adjust your Shutter Speed and Aperture until detail does begin to be lost, then step back your exposure slightly, making the photograph a little bit darker.

If any Specular Highlights such as reflections of the light sources such as the sun are clipped/ blown out, this isn’t too important. If your camera has a Highlights Warning feature, detail in your picture that has blown out and lost detail will flash.

The best way to check your exposure is by using your Histogram. Hopefully, your camera provides separate histograms for the Red, Green and Blue channels. If it doesn’t, be a little more conservative with your exposure (keep things a tiny bit darker).

Why? Because when the camera only provides one histogram, it’s often just the green channel or a combination of all three. Therefore, if there are a lot of bright red tones in your photograph, you won’t see a Highlight warning and detail in these red areas can inadvertently be over-exposed and blown-out. This is a common mistake for people photography and ruins natural skin tones.

So, increase your exposure using your Aperture, Shutter Speed and possibly ISO Sensitivity until one of your colour histograms starts to ‘blow out’ and lose detail; then darken your exposure a tiny bit.

You now have the correct exposure for the light you’ve just set your camera for (where you’re pointing it, not where you’re standing).