The photographic image has a profound effect on our understanding of the human condition. Photography is an indispensible means by which people experience the present, encounter the future and make sense of the past. It has a particular utility for documenting history.
The photographic image helps us with an understanding of people and events we would never meet or experience. It allows us to witness places and things of the natural world that we would not otherwise see.
Photography provides us with powerful and sometimes beautiful evidence of the resources and achievements of modern life. Photographs capture physical, emotional and cultural details, from the distant and strange to the immediate and familiar.
We keep images of our likeness in youth and old age and the likenesses and memories of people we might never see again. Photography documents, makes art, advertises, contributes to, explains and illustrates science, aids business, entertains and has the power to change our minds, to convince us.
Photography trades in volume with millions of photographs created every day that form a visual inventory of our lives and culture. If you haven’t previously thought of the importance of the photographic and moving images, try thinking of a world without them.
Talking point – camera controls
A photograph is made with an exposure to light recorded by the image sensor in the camera. Understanding how your camera controls exposure is the key to taking more creative photographs.
Exposure is controlled by three variables:
1 shutter speed
3 ISO setting.
Each variable has a specific individual effect on the photograph. Shutter speed affects motion blur. Aperture affects the depth of field (the distance from the a camera that is in focus). ISO settings affect the level of digital ‘noise’, with higher ISO settings giving more noise in the photograph.
By using different combinations of these three variables you can achieve the exposure needed but with a different look and feel to the photograph.
Most digital cameras have standardised exposure modes. Each mode influences how shutter speed, aperture and ISO are chosen for a given exposure. Some modes attempt to pick all three values for you, whereas others let you specify one setting and the camera picks the other two (if possible).
The typical modes and their uses are:
- Auto [A] – the camera automatically selects all exposure settings
- Program [P] – the camera automatically selects aperture and shutter speed, but you can choose exposure compensation and ISO
- Aperture Priority [Av] – you specify the aperture and ISO; the camera’s inbuilt light meter determines the shutter speed
- Shutter Priority [Tv] – you specify the shutter speed and ISO; the camera's metering determines the corresponding aperture
- Manual [M] – you specify the aperture, ISO and shutter speed regardless of whether these values lead to a correct exposure
- Bulb [B] – you specify the aperture and ISO; the shutter speed is determined by a remote release switch, or by the period until you press the shutter button a second time
Av, Tv and M are often called ‘creative modes’ or auto exposure (AE) modes. On some cameras Program (P) can also act as a hybrid of Av and Tv modes.
Compact cameras offer a range of preset exposures represented with symbols as follows.
- Tulip – macro setting for close-up photography
- Face – optimum setting for portrait photography
- Mountain – optimum setting for landscape photography
- Person with a star – nighttime portraits where ambient low light is balanced with flash illumination.
- SCN – (short for ‘scene’) optimum settings for a given subject (beach, snow, sports action, fireworks, sepia, black and white)
- Movie camera – movie mode.
Decisions on which exposure mode to use will affect other variable such as the need for a tripod (to reduce camera shake), the depth of field, motion blur and repeatability. Check your camera guide for further details:
So now you can experiment with different settings. What will you try first?