How to choose an exposure mode

Exposure Lesson #1: How to Choose an Exposure Mode

Many digital SLRs and mirrorless cameras have several fully automatic exposure modes. These are aimed at people who know very little about photography. If you don’t know the difference between an f-stop and ISO, then it is quicker and easier to use modes like Landscape or Portrait than it is to learn how your camera works.

On most cameras there is a Mode Dial that lets you set the exposure mode. Notable exceptions are high end professional cameras (such as the Nikon D810 and Canon EOS 1D X Mark II) and the Fujifilm X series cameras.

This photo shows the Mode Dial of a Canon EOS Rebel T6 (known as the EOS 1300D in Europe).

EOS Digital Rebel T6 mode dial

The fully automatic exposure modes are represented by the green square with the A inside and the picture icons. The head represents portrait mode, the mountain and cloud icon landscape mode, and so on. There’s even a food mode (that’s the knife and fork mode). Presumably that’s for foodies with an Instagram account.

These exposure modes are fairly straightforward. Choose landscape mode and the camera will try and set a small aperture (for good depth of field), a low ISO and disable the flash. Select portrait mode and it will select a wide aperture (for good bokeh) and activate the flash in low light. Choose food mode and “the photo will look bright and appetizing” (that’s a quote from the instruction manual).

Why you shouldn’t use a fully automatic exposure mode

Personally I think fully automatic exposure modes do more harm than good. They clutter up the Mode Dial and offer too many choices.

They can also be quite restrictive. For example, on Canon EOS cameras you can’t adjust the ISO in any of these modes. You can’t change the camera profile, or apply exposure compensation if the camera gets exposure wrong. The camera sets file type to JPEG and you can’t use Raw. You can’t even decide whether to use the camera’s flash. The camera makes all those decisions for you.

Other cameras may have less restrictive fully automatic modes, but they still make the creative decisions for you.

It’s convenient, but it’s not what creative photography is all about.

The SLR and mirrorless camera difference

Think about why you bought a digital SLR or mirrorless camera in the first place. One is to explore the creative possibilities offered by different lenses.

Another is because these cameras give you complete creative control.

But to gain creative control you have to learn to set the ISO, aperture and shutter speed yourself. You need to understand what each of these settings does.

Thankfully, this is quite basic. Once you do so, you’re getting involved in the creative side of photography.

This is exciting because you are starting to make photos, rather than just take them. And that’s what you bought your camera for, right?

Why pro cameras don’t have fully automatic exposure modes

Cameras aimed at advanced hobbyists and professional photographers don’t have these beginner modes. That should tell you all you need to know about how useful they are for serious photography.

This is the Mode Dial of the Canon EOS 5D S.

Canon EOS 5D S mode dial

It has one fully automatic mode only (represented by the green square). It also has the four modes used by most photographers.

  • Programmed auto (P)
  • Shutter priority (Tv)
  • Aperture priority (Av)
  • Manual (M)

Note: Most manufacturers use the letter S for Shutter Priority and A for Aperture Priority. The exceptions are Canon and Pentax, who use Tv (Time value) and Av (Aperture value).

There is also a B (for Bulb mode) and three user customizable modes (C1, C2 and C3).

You can see that this is a far simpler approach.

Programmed auto, aperture priority, shutter priority & manual exposure modes

So, how do you use your camera creatively? The best and easiest way is to stick with the four main exposure modes: programmed auto, shutter priority, aperture priority and manual.

Programmed auto

Programmed auto is similar to using your camera in fully automatic. The difference is that programmed auto hands control back to you by letting you make creative decisions like setting camera profile, applying exposure compensation or using flash.

Most cameras also have a Program Shift tool that lets you change the exposure settings selected by the camera.

For example, if your camera has set f5.6 at 1/500 second (at ISO 400) and you want a larger aperture, you can use exposure shift to change the settings to f2.8 at 1/2000 second. The exposure is the same but the effect is different.

I don’t use program much myself, but it’s very useful and shouldn’t be overlooked.

Note: Programmed auto is the term used by Nikon. Canon, Fujifilm and Sigma use program AE, Sony uses program auto, Olympus uses program shooting and Pentax uses hyper-program.

This is the type of photo that could easily be taken in programmed auto mode. The goal is simply to take an interesting photo. The specific aperture and shutter speed settings are not particularly important.

Statue in cemetery in Punta Arenas, Chile

Manual

I use manual mode a lot. It’s so useful that it deserves a lesson to itself. You can read it at Exposure Lesson #4: Manual Mode.

Aperture priority

In aperture priority, you select the aperture and ISO and your camera sets the shutter speed. You can control the shutter speed indirectly by changing the ISO.

Aperture priority is suitable for the following subjects.

Landscape photography

Depth of field is important in landscape control. Normally you want the entire scene to be in sharp focus. The best way to do this is to set a small aperture (like f11 or f16) and a low ISO (for the best image quality).

This may give a shutter speed that is too low to hand-hold the camera without camera shake. In this case you can either raise the ISO (to get a faster shutter speed) or use a tripod.

If you’re not convinced already here are some more reasons why you would want to use aperture priority instead of landscape mode.

  • You can apply exposure compensation if the camera gets the exposure wrong.
  • You can set the camera profile you prefer to use, not the one your camera thinks you should use.
  • You can set the camera to use the Raw format, for better image quality.
  • You can make sure your camera uses the lowest available ISO setting, again for image quality.

Use aperture priority to create landscape photos like this, made with an aperture of f6.3 (small enough for a hand-held photo taken with a wide-angle lens on an APS-C camera).

Landscape photo made in the Andes in south-west Bolivia.

Portrait photography

You can also use aperture priority for making portraits with bokeh. This is particularly effective if you use prime lenses (or have a f2.8 aperture zoom). Set the aperture to f2.8 (or thereabouts), focus on the model’s eyes and let everything else go out of focus.

The advantage of using aperture priority is that you can adjust the aperture to give more or less depth of field. It gives you complete creative control.

Here’s an example of a portrait taken at f2.8.

Portrait taken with 85mm lens set to f2.8 in aperture priority

Close-up and macro photography

The closer you get to your subject with your lens the less depth of field there is at any given aperture setting. That makes aperture critical. Depending on your creative goals, you might want to use a wide aperture to throw the background out of focus and create beautiful bokeh. Or you might want to use a small aperture to give more depth of field.

Either way, you can control shutter speed indirectly by changing the ISO setting. This is important as you need a fast shutter speed to prevent blur caused by camera shake.

I made this photo using an aperture of f2.8.

A close-up photo of a red flower made in aperture priority

Shutter priority

In shutter priority, you select the shutter speed and ISO and your camera sets the aperture. You can control aperture indirectly by changing the ISO.

I often use shutter priority when I’m hand-holding the camera. It lets me set a shutter speed fast enough to prevent camera shake. I increase ISO if I need more depth of field.

Shutter priority is suitable for the following subjects.

Street and travel photography

Shutter priority comes in useful for travel and street photography, where aperture and depth of field are not as important as using a fast shutter speed to prevent camera shake.

I made this photo using shutter priority and a shutter speed of 1/125 second.

A street photo taken in shutter priority mode in Shanghai, China

Action and wildlife photography

Shutter priority comes in useful when shooting action or moving wildlife. You need to use a shutter speed fast enough to freeze the action and prevent camera shake with telephoto lenses.

I made this photo using shutter priority and a shutter speed of 1/1000 second. It was fast enough to freeze the motion of the galloping horse and rider.

A photo taken in shutter priority of a knight riding a horse in a jousting tournament at Blenheim Palace, Oxfordshire.

Panning

Another example of where you could use shutter priority is for exploring intentional camera movement – photos made by selecting a slow shutter speed and deliberately moving the camera during the exposure.

I made this photo at a beach in Spain using this technique. I set a shutter speed of one second and panned the camera from right to left. You can use panning techniques to create blurred photos of all sorts of interesting subjects.

A creative landscape photo made by panning the camera in shutter priority

Creative Exercises

Now it’s time to put these tips into practice with some creative exercises.

Aperture priority

Choose a lens, put your camera into aperture priority mode and set the widest aperture on the lens. This works best with a prime lens but you can also do it with a zoom.

Make some photos at this setting. The subject can be anything you like, but portraits and close-ups are a good place to start. What happens to the background as you get closer to your subject? What happens if you move your subject away from the background?

I made this photo of a lizard with an aperture of f1.8. The wide aperture defocused the background completely. This makes the lizard the focal point of the photo even though it’s positioned in the bottom right corner.

Photo of a lizard made with aperture priority

Shutter priority

Now try a similar exercise in shutter priority. There are two extremes to try.

1. Set a fast shutter speed and use it to freeze action.

2. Use a slow shutter speed to turn something that moves into a blur.

I made this photo of a waterfall with a shutter speed of four seconds. You need to put the camera on a tripod to make photos like this without camera shake.

A landscape photo of a waterfall in Covedonga, Spain made with shutter priority

You can try these techniques out over a period of time. The aim is to get used to using the aperture and shutter priority modes on your camera, and take creative control by selecting the aperture or shutter speed setting yourself.

This is the first in a series of lessons about exposure for digital cameras. I’ll add links to new lessons here as I publish them.

Further reading

Exposure Lesson #2: Why Cameras Get Exposure Wrong

Exposure Lesson #3: Does the Metering Mode Matter?

Exposure Lesson #4: Manual Mode

Exposure Lesson #5: How to Read a Camera Histogram

Exposure Lesson #6: Exposing to the Right

Mastering Exposure ebook coverMastering Exposure

Have you ever wondered why your digital camera has so many exposure modes, and what each one does? Or why it’s so easy to under- or overexpose your photos even with the latest cameras and most advanced evaluative or matrix metering modes? Learn the answers to these questions and more in my newest ebook Mastering Exposure.

 

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About Andrew S. Gibson

Andrew S. Gibson is a writer, publisher, traveler and photographer based in the UK. He started writing about photography while traveling in Bolivia, and has been published in many prestigious photography magazines including EOS magazine, where he worked as a Writer and Technical Editor for two years. He currently writes for The Creative Photographer, Digital Photography School and Craft & Vision. He is inspired by meeting new people, seeing new places and having new experiences.

Comments

  1. Excellent description and examples. Very helpful,
    Thank you.

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