Top of camera controls (left) - Exposure Mode Dial

Situated on the top of the camera on the left hand side is the exposure mode dial. This controls the manner of exposure operation be it fully automatic, a preprogrammed scene composition, flexible program or a range of manual and semi-automatic options.

In the user manual Canon breaks these exposure modes into two groups; Basic Zone and Creative Zone.

Basic zone exposure modes

Full Auto and the six scene exposure modes are collectively referred to as the 'Basic Zone'. In all of these modes the following camera options are either disabled or limited:

• Flash mode
• AF mode
• Drive mode
• White Balance
• ISO Sensitivity
• Metering Mode
• Flash Compensation
• Exposure Compensation
• Focus Point selection
• Parameters
• Custom Functions
• AE Lock
• AE / WB Bracketing
• RAW image format 		[ Refer to table below ]
[ Refer to table below ]
[ Refer to table below ]
[ Auto ]
[ Auto ]
[ Evaluative ]
[ 0 EV ]
[ 0 EV ]
[ Auto ]
[ Standard ]
[ unavailable ]
[ unavailable ]
[ unavailable ]
[ unavailable ]

In the basic zone the camera will indicate that blur may occur because of slow shutter speeds, it does so by blinking the shutter speed on the LCD panel and viewfinder status bar.

Icon Mode AF mode Drive mode Flash mode
Fully Automatic Exposure

Camera has complete control over exposure, point-and-shoot operation. 		• AI Focus • Single
• Self-Timer		 • Auto
• Red-eye
Portrait

Apertures are kept as large as possible (small F number) to produce a shallow Depth of Field (blurred background). 		• One Shot • Continuous
• Self-Timer 		• Auto
• Red-eye
Landscape

 Apertures as small as possible (large F numbers) for the largest depth of field.		 • One Shot • Single
• Self-Timer		 • Disabled
Close-up (Macro)

Aperture is kept to a medium setting to ensure the subject DOF is deep enough but the background is blurred.		 • One Shot • Single
• Self-Timer		 • Disabled
Sports

Shutter speed is kept as high as possible to ensure capture of fast moving objects.		 • AI Servo • Continuous
• Self-Timer 		• Disabled
Night Scene

Allows for slow shutter speeds combined with flash to illuminate foreground and background.		 • One Shot • Single
• Self-Timer		 • Manual
• Red-eye
Flash off

Disables internal and external flash for taking automatic slow exposures.		 • AI Focus • Single
• Self-Timer		 • Disabled

Creative zone exposure modes

The five exposure modes will be more familiar (and preferred) by most prosumer / professionals. All menu functions and camera settings are available in these modes and can be used in any combination.

Icon
Description

Program Auto Exposure (Flexible)

Very similar to AUTO exposure but you have access to all the normal manual controls, can set the ISO, exposure compensation, use AE lock, bracketing etc. The Program AE on the EOS 20D is flexible, that means that you can select one of a variety of equal exposures by turning the main dial (top of camera). Example:
       
 • 1/30 F2.8 (metered)
 • 1/20 F3.2 (turn left one click)
 • 1/15 F4.0 (turn left two clicks) etc.

Shutter Priority Auto Exposure

In this mode you select the shutter speed and the camera will calculate the correct aperture for the exposure (depending on metered value; metering mode, ISO). Shutter speed is displayed on the viewfinder status bar and on the top LCD, turn the main dial to select different shutter speeds. A half-press of the shutter release causes the camera's exposure system to calculate the aperture, if it's outside of the camera's exposure range the aperture will blink. Available shutter speeds below represent 1/3 stop increments, 1/2 stop increments can be selected via custom function 6.

1/8000, 1/6400, 1/5000, 1/4000, 1/3200, 1/2500, 1/2000, 1/1600, 1/1250, 1/1000, 1/800, 1/640, 1/500, 1/400, 1/320, 1/250, 1/200, 1/160, 1/125, 1/100, 1/80, 1/60, 1/50, 1/40, 1/30, 1/25, 1/20, 1/15, 1/13, 1/10, 1/8, 1/6, 1/5, 1/4, 0.3, 0.4, 0.5, 0.6, 0.8, 1, 1.3, 1.6, 2, 2.5, 3.2, 4, 5, 6, 8, 10, 13, 15, 20, 25, 30 sec

Aperture Priority Auto Exposure

In this mode you select the aperture and the camera will calculate the correct shutter speed for the exposure (depending on metered value; metering mode, ISO). Aperture is displayed on the viewfinder status bar and on the top LCD, turn the main dial to select different apertures. A half-press of the shutter release causes the camera's exposure system to calculate the shutter speed, if it's outside of the camera's exposure range the shutter speed will blink. Available apertures will differ depending on the lens used, the list below represent 1/3 stop increments, 1/2 stop increments can be selected via custom function 6.

F1.0, F1.1, F1.2, F1.4, F1.6, F1.8, F2.0, F2.2, F2.5, F2.8, F3.2, F3.5, F4.0, F4.5, F5.0, F5.6, F6.3, F7.1, F8.0, F9.0, F10, F11, F13, F14, F16, F18, F20, F22, F25, F29, F32, F36, F40, F45, F51, F57, F64, F72, F81, F91 (exact range depends on lens used)
Full Manual Exposure

In this mode you select the aperture and the shutter speed from any combination of the above (plus BULB for shutter speed, apertures limited by the lens used). Top dial selects shutter speed, rear dial selects aperture. Half-press the shutter release and the meter on the viewfinder status bar and top LCD will reflect the exposure level compared to the calculated ideal exposure, if it's outside of +/- 2EV the indicator bar will blink either + or -.

Automatic Depth-Of-Field AE

This mode, seen before on other Canon EOS cameras automatically controls the depth of field to ensure that all the subjects covered by the focusing points, from those close to the camera to those far away from the camera remain sharply defined (are within the depth of field).

Top of camera controls (right)

Top of the camera on the right side is the status panel LCD, directly above this are four buttons (LCD panel backlight, AF/WB, Drive/ISO, Metering/Flash compen.) In front of these buttons is the main dial and shutter release button.

Settings buttons are press once, turn a dial to change setting value and then half-press the shutter release to return to shooting mode (or press another button).

The table below shows the relationship between each of the settings buttons and the parameters changed by either turning the main dial (top) or quick control dial (rear).

Button Main Dial
 Quick Control Dial

Auto Focus Mode

 • One Shot (focus lock on half-press)
 • AI Focus (locks but monitors movement)
 • AI Servo (continuous predictive focus)

AI Focus mode initially locks just like One Shot mode but monitors the focused subject, if the subject moves it will automatically switch to an AI Servo operation.

 White Balance Mode

 • Auto (3000 - 7000 K)
 • Daylight (~ 5200 K)
 • Shade (~ 7000 K)
 • Cloudy (~ 6000 K)
 • Tungsten (~ 3200 K)
 • Fluorescent (~ 4000 K)
 • Flash (~ 6000 K)
 • Custom (2000 - 10000 K sample)
 • Kelvin temperature (2800 - 10000 K)

Metering Mode

 • Evaluative (35 zone)
 • Partial (9.5% of screen)
 • Center Weighted Average

 Flash Compensation

 • +/-2 EV
 • 1/3 or 1/2 EV steps (C.Fn 6)
Drive Mode

 • Single shot
 • Continuous (5 fps, 23 frames JPEG)
 • Self-Timer

Self-Timer delay is by default 10 seconds, however if you use mirror lockup (C.Fn 12) the delay is reduced to 2 seconds.
 ISO Sensitivity

 • 100
 • 200
 • 400
 • 800
 • 1600
 • H (3200) (enabled via C.Fn 8)