Mode A (Aperture-Priority Auto)
In aperture-priority auto, you choose the aperture from values between the minimum and maximum for the lens while the camera automatically selects the shutter speed that will produce the optimal exposure. Small apertures (high f/-numbers) increase depth of field, bringing both the main subject and background into focus. Large apertures (low f/-num- bers) soften background details.
To take photographs in aperture-priority auto:
1 Rotate the mode dial to A.
2Rotate the sub-command dial to choose the desired aperture.
3Frame a photograph, focus, and shoot.
Depth of Field
“Depth of field” is the distance to which objects behind and in front of the focus point appear to be in focus. Large apertures (low f/-numbers) reduce depth of field, blurring objects behind and in front of the main subject. Small apertures (high f/-numbers) increase depth of field, bringing out details in the background and foreground (note that depth of field is also influenced by other factors, such as focal length and focus distance). Short field depths are generally used in portraits to blur background de- tails, long field depths in landscape photographs to bring the foreground and background into focus.
To preview depth of field, press and hold the depth-of-field preview but- ton. The lens will be stopped down to the current aperture value, allowing depth of field to be previewed in the viewfinder.
Reference: P, S, A, and M Modes / Mode A (Aperture-Priority Auto) 49