Canon Eos Rebel T2i 550d Instruction Manual

81
f: Changing the Depth of Field
 When using an aperture with  a high f-number, note that camera 
shake can occur in low light scenes.
A higher aperture f-number will ma ke the shutter speed slower. 
Under low light, the shutter speed ca n be as long as 30 sec. In such 
cases, increase the ISO speed and hol d the camera steady or use a 
tripod.
  The depth of field depends not on ly on the aperture, but also 
the lens and subject distance.
Since wide-angle lenses have a wide depth of field (range of...

f: Changing the Depth of Field
82
To obtain a correct flash expos ure, the flash output will be set 
automatically to match the set a perture (autoflash exposure). The 
shutter speed will be set automatically  between 1/200 sec. - 30 sec. to 
suit the scene’s brightness.
In low light, the main subject is ex posed with the automatic flash, and 
the background is exposed with a slow  shutter speed set automatically. 
Both the subject and background look properly exposed (automatic 
slow-speed flash sync)....

83
You can set both the shutter speed and aperture manually as desired. 
With flash, the flash exposure will  be set automatically to match the 
aperture that was set. The flash sync speed can be set within 1/200 
sec. to 1/30 sec. or to bulb.
* < a> stands for Manual.
1Set the Mode Dial to < a>.
2Set the shutter speed and 
aperture.
  To set the shutter speed, turn the 
 dial.
  To set the aperture, hold down the 
 button and turn the < 6> 
dial.
3Set the exposure and take the 
picture.
  The exposure...

a: Manual Exposure
84
In step 2  on the preceding page, turn the 
 dial to the left to set < BULB>. A 
bulb exposure keeps the shutter open for 
as long as you hold down the shutter 
button. It can be used to photograph 
fireworks, etc. The elapsed exposure 
time will be displayed on the LCD 
monitor.
Bulb Exposures
  Since bulb exposures produce more noise than usual, the image might 
look a little grainy.
  You can reduce this noise by setting the [ 7 Custom Functions (C.Fn) ] 
menu’s [Long exp. noise...

85
Objects in the foreground and background will be in focus automatically. 
All the AF points will function to  detect the subject, and the aperture 
required to attain the necessary dept h of field will be set automatically.
*  stands for Auto-Depth  of field. This mode sets the depth of field automatically.
1Set the Mode Dial to < 8>.
2Focus the subject.
 Aim the AF points over the subjects 
and press the shutter button halfway 
(0 ).
  All the subjects covered by the AF 
points flashing in red will...

86
The metering mode measures the subject’s brightness to determine the 
correct exposure. Normally, evaluative metering is recommended.
1Select [Metering mode].
 Under the [ 2] tab, select [Metering 
mode ], then press < 0>.
2Set the metering mode.
  Press the < U> key to select the 
metering mode, then press < 0>.
q Evaluative metering 
This is an all-around metering mode suited for 
portraits and even backlit subjects. The camera 
sets the exposure automatically to suit the 
scene. This metering mode...

87
Set exposure compensation if the exposure (without flash) does not come out as 
desired. This feature can be us ed in Creative Zone modes (except ). Although 
you can set the exposure com pensation up to ±5 stops in 1/3-stop increments, the 
exposure compensation indica tor in the viewfinder can only display the setting up to 
±2 stops. If you want to set the exposur e compensation beyond ±2 stops, you should 
follow the instructions for [2 Exp. comp./AEB ] on page 89.
Making it brighter:
Hold down...

Setting Exposure CompensationN
88
Set flash exposure compensation if  the flash exposure of the subject 
does not come out as desired. You can set the flash exposure 
compensation up to ±2 stops in 1/3-stop increments.
1Display the Quick Control screen.
  With the shooting settings displayed, 
press the < Q> button (p.38).
X The Quick Control screen will activate 
(7 ).
2Select [ y].
 Press the < S> key to select [ y*].
X [Flash exposure comp.] will be 
displayed at the bottom.
3Set the flash exposure...

89
This feature takes exposure compensation a step further by varying the 
exposure automatically with three shots (±2 stops in 1/3-stop 
increments) as shown below. You can then choose the best exposure. 
This is called AEB (Auto Exposure Bracketing).
1Select [Expo. comp./AEB].
  Under the [ 2] tab, select [Expo. 
comp./AEB ], then press < 0>.
2Set the AEB amount.
  Turn the < 6> dial to set the AEB 
amount.
  Press the < U> key to set the 
exposure compensation amount. If 
AEB is combined with exposure...

3 Auto Exposure BracketingN
90
 Follow steps 1 and 2 to turn off the AEB amount display.
  The AEB setting will be canceled automatically if the power switch is 
set to < 2>, flash recycling is complete, etc.
  Using AEB with continuous shooting.
If  continuous shooting (p.70)  has been set and you press the 
shutter button completely, the three bracketed shots will be taken 
continuously in this sequence : Standard exposure, decreased 
exposure, and increased exposure.
  Using AEB with < u> single...