1. Shooting modes

The best place to start is with shooting modes. The shooting modes will most likely be found on a dial labelled with ‘auto, Av, Tv, P, M’ and maybe more. Selecting a shooting mode will determine how your camera behaves when you press the shutter, for example, when ‘auto’ is selected, the camera will determine everything to do with the exposure, including the aperture and shutter speed. The other modes, ‘Av, Tv, P, M’, are there to give you control:

Don’t worry if your mode dial looks a little different; different manufacturers use different abbreviations for the shooting modes. Your mode dial may have the letters ‘A, S, P, M’ (instead of Av, Tv, P, M), yet they all function in the same way. Below, I have given each abbreviation for the given mode.

Aperture Priority (Av or A)
Aperture priority can be thought of as a ‘semi-automatic’ shooting mode. When this is selected, you as the photographer set the aperture and the camera will automatically select the shutter speed. So what is aperture and when would you want to control it?

The aperture is the size of the opening in the lens through which light is allowed to pass whenever the shutter is opened – the larger the aperture, the more light passes through.

The aperture is measured in ‘f-stops’ and is usually displayed using an ‘f-number’, e.g. f/2.0, f/2.8, f/4.0, f/5.6, f/8.0 etc, which is a ratio of focal length over diameter of the opening. Therefore, a larger aperture (a wider opening) has a smaller f-number (e.g. f/2.0) and smaller aperture (a narrower opening) has a larger f-number (e.g. f/22). Reducing the aperture by one whole f-stop, e.g. f/2.0 to f2/8 or f/5.6 to f/8.0, halves the amount of light entering the camera.

Aperture is one of the most important aspects of photography as it directly influences the depth of field – that is, the amount of an image that is in focus. A large depth of field (achieved by using a small aperture (large f-number)) would mean that a large distance within the scene is in focus, such as the foreground to the background of the landscape below.

An aperture of f/13 was used here to give a large depth of field, ensuring that the whole image, from the foreground grasses to the background mountains. was sharp

Whereas a shallow depth of field (achieved by using a large aperture (small f-number)) would produce an image where only the subject is in sharp focus, but the background is soft and out of focus. This is often used when shooting portraiture or wildlife, such as the image below, to isolate the subject from the background:

A large aperture of f/4.5 was used to capture this water vole, against a soft, out of focus background

So when using aperture priority, you can get complete control over your depth of field, whilst the camera takes care of the rest.

Shutter Priority (Tv or S)
Similarly to aperture priority, this is another ‘semi-automatic’ shooting mode, though in this instance, you as the photographer set the shutter speed and the camera will take care of the aperture. The shutter speed, measured in seconds (or more often fractions of a second), is the amount of time the shutter stays open when taking a photograph. The longer the shutter stays open, the more light passes through to the sensor to be captured.

You would select a short shutter speed if you wanted to freeze a fast moving subject, such as shooting sports, action or wildlife, for example:

A very fast shutter speed of 1/4000th sec was used to freeze the motion of this grouse in flight

You would use a long shutter speed if you wanted to blur a moving subject, for example water rushing over a waterfall (slower shutter speeds will require you to put the camera on a tripod to ensure the camera is held steady whilst the shutter is open):

To capture the motion of the waves, and render the water with a soft, milky texture, a shutter speed of 6 seconds was used here

So whilst you worry about what shutter speed you need for a given photograph, the camera will determine the appropriate aperture required to give the correct exposure.

Aperture and shutter priority shooting modes may be semi-automatic, meaning that some may deride their use because they’re not fully manual, however they are incredibly useful modes to shoot in that can give you enough creative control to capture scenes as you envisage them.

Program (P)
Program mode is almost a halfway house between the semi automatic modes of aperture/shutter priority and full manual control. In program mode, you are able to set either the aperture or shutter speed, and the camera will maintain the correct exposure by adjusting the other one accordingly, i.e. as you change the aperture, the shutter speed will automatically change, and vice versa. This gives you additional freedom that using either aperture priority or shutter priority cannot give without switching between shooting modes.

Manual (M)
Manual mode is exactly what it sounds like, you are given full control over the exposure determination, setting both the aperture and shutter speed yourself. There will be an exposure indicator either within the viewfinder or on the screen that will tell you how under/over exposed the image will be, however, you are left to change the shutter speed and aperture yourself to ensure you achieve the correct exposure.

Practically Speaking: as a first step to taking your camera off ‘auto’, aperture priority and shutter priority modes offer two very simple ways to start to understand how the different setting impact your images and are a perfect starting place for learning how to use your camera more creatively.