Creating better pictures: Various exposure modes

Various Exposure Modes

In "Understanding Exposure" we explained how different combinations of aperture and shutter speed capture totally different images of the same subject. For such fast-moving subjects as racing cars, you can freeze the action on film by using shutter speeds of 1/500 or 1/1000 sec. Or try panning the camera to follow the subject when using a slow shutter speed of about 1/60 sec. The background will appear to be smeared in the photograph, enhancing the impression of the car's speed.

Exposure mode
Most new AF SLR cameras feature four or five exposure modes, usually including programmed auto exposure mode, aperture-priority auto exposure mode, shutter-priority auto exposure mode and manual exposure mode.

Exposure modes and characteristics

Programmed exposure mode (P mode)
In this mode, camera automatically chooses combination of aperture and shutter speed to assure optimal exposure, even if subject brightness changes.

Note: When using a Nikon SLR camera featuring P mode with a CPU lens (AF Nikkor or AI-P Nikkor lens), set the lens aperture ring to the minimum aperture (highest f-number). Otherwise, the shutter may not operate correctly, or the aperture may not be displayed in the viewfinder, depending on the camera/lens combination.

Example 1

Advantages of P mode
You don't have to worry about setting aperture and shutter speed -- P mode assesses the shooting situation and makes those settings for you. By making your SLR as easy to use as a compact camera, P mode is suitable for shooting snapshots of parties and other events in which you don't want to miss your shot.

Vari-Program mode (Ps mode)
Note: Different manufacturers have different names for this mode.

Using Ps mode is fundamentally similar to using P mode, but "scenery" or "flower" mark selections, for example, are specifically designed to simplify settings for shooting certain types of subjects.

Shutter-priority auto mode (S mode)
Select a shutter speed, and the camera automatically adjusts the aperture for optimal exposure.

Note: With Nikon SLR cameras, the aperture setting method is the same as the program mode.

Example 2

Advantages of S mode
S mode is ideal for shooting sports and other fast-moving action -- to freeze subject motion using a high shutter speed, or to capture a blur of motion using a low shutter speed.

Aperture-priority auto mode (A mode)
Using A mode, select the desired aperture, and the camera automatically adjusts shutter speed for optimal exposure.

Advantages of A mode
A mode gives you control over depth of field, so you have flexibility in focusing as you wish on foreground (for portraits, etc.), background (for a faraway face in the crowd, etc.), or both (for landscapes, in which you want the entire image to appear in sharp focus).