Canon Eos Rebel T2i 550d Instruction Manual

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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 
acceptable focus in front of and beh ind the point of focus), you need 
not set a high aperture f-number to  obtain a sharp picture from the 
foreground to the background. On the other hand, a telephoto lens 
has a narrow depth of field.
And the closer the subject, the narro wer the depth of field. A farther 
subject will have a wider depth of field.
  Set the aperture so that the  shutter speed display does not 
blink in the viewfinder.
If you press the shutter  button halfway and change 
the aperture while the shutter speed is displayed, 
the shutter speed display will also change to 
maintain the same exposure (amount of light 
reaching the image sensor). If you exceed the 
adjustable shutter speed  range, the shutter speed 
display will blink to indicate that the standard 
exposure cannot be obtained.
If the picture will be too dark, the “ 30” (30 sec.) shutter speed 
display will blink. If th is happens, turn the < 6> dial to the left to set 
a lower aperture f-number or increase the ISO speed.
If the picture will be too bright, the “ 4000” (1/4000 sec.) shutter 
speed display will blink.  If this happens, turn the < 6> dial to the 
right to set a higher aperture f-number or decrease the ISO speed.
Shooting Tips
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							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). If you ar e handholding the camera, keep it 
steady to prevent camera shake. Using a tripod is recommended.
If you do not want a slow shu tter speed to be used, set the [ 7 Custom 
Functions (C.Fn) ] menu’s [Flash sync. speed in Av mode ] to [1: 1/
200-1/60 sec. auto ] or [2: 1/200 sec. (fixed) ] (p.192).
Press the depth-of-field preview button 
to stop down to the lens’s current 
aperture setting. You can then check the 
depth of field (range of acceptable focus) 
through the viewfinder.
Using the Built-in Flash
Depth of Field Preview N
The depth-of-field effect  can be clearly seen on th e Live View image as you 
change the aperture and pr ess the depth-of-field preview button (p.112).
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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 level indicator in the 
viewfinder indicates the exposure 
level up to ±2 stops from the standard 
exposure index at the center. While 
you change the shutter speed and 
aperture, the exposure level mark will 
move. You can decide which 
exposure level to set. If the amount 
set exceeds ±2 stops, the end of the 
exposure level indicator will display 
 or < J>.
a: Manual Exposure

 + 
Exposure level markStandard exposure index
If the [
2 Auto Lighting Optimizer ] (p.103) is set to anything other than 
[ Disable ], the image may still look bright ev en if a darker exposure has been 
set.
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							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 reduction ] to [1: Auto ] or [2: On ] (p.193).
 For bulb exposures, using a tripod  and Remote Switch (p.204, 205) is 
recommended.
  You can also use a remote  controller (sold separately, p.204) for bulb 
exposures. When you press  the remote controller’s transmit button, the 
bulb exposure will star t immediately or 2 sec.  later. Press the button 
again to stop the bulb exposure.
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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 be in focus.
3Take the picture.
 The aperture display in the viewfinder blinks.
The exposure is correct, but the desired depth of field cannot be 
obtained. Either use a wide-angle lens  or move farther away from 
the subjects.
  The shutter speed display in the viewfinder blinks.
If the “ 30” shutter speed blinks, it means  that the subject is too dark. 
Increase the ISO speed. If the “ 4000” shutter speed blinks, it means 
that the subject is too bright. Decrease the ISO speed.
  A slow shutter speed has been set.
Use a tripod to steady the camera.
  I want to use flash.
Flash can be used, however, the result will be the same as using the 
 mode with flash. The desired depth of field will not be obtained.
8 : Automatic Depth-of-Field AE
FAQ
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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 is set automatically 
in Basic Zone modes.
w  Partial metering
Effective when the background is much brighter 
than the subject due to backlighting, etc. The 
gray area in the figure is  where the brightness is 
metered to obtain the standard exposure.
r  Spot metering
This is for metering a specific part of the subject 
or scene. The gray area in the left figure is 
where the brightness is metered to obtain the 
standard exposure. This metering mode is for 
advanced users.
e Center-weighted average metering
The brightness is metered at the center and 
then averaged for the entire scene. This 
metering mode is for advanced users.
q  Changing the Metering Mode N
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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 the < O> button and 
turn the < 6> dial to the right. 
(Increased exposure)
Making it darker: Hold down the < O> button and 
turn the < 6> dial to the left. 
(Decreased exposure)
X As shown in the figure, the exposure 
level is displayed on the LCD monitor 
and in the viewfinder.
  After taking the picture, hold down 
the < O> button and turn the 
< 6 > dial to reset the exposure 
compensation to zero.
Setting Exposure Compensation N
O Setting Exposure Compensation
Decreased exposure for a darker image
Increased exposure for a brighter image
If the amount set exceeds ±2 stops, th e end of the exposure level indicator 
will display < I> or < J>.
Dark exposure Brighter with increased exposure
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							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 
compensation amount.
 To make the flash expos ure brighter, turn the 
 dial to the right.  (Increased exposure)
Or to make it darker, turn the < 6 > dial to 
the left. (Decreased exposure)
X When you press the shutter button halfway, the < y> will appear in 
the viewfinder.
  After taking the picture, do steps 1 to 3 to return the flash 
exposure compensation amount to zero.
y  Flash Exposure Compensation N
If the [2 Auto Lighting Optimizer ] (p.103) is set to anything other than 
[ Disable ], the image may look bright even if a decreased exposure 
compensation or flash exposure  compensation has been set.
 You can also set and cancel the flash exposure compensation with the 
[1  Flash control ] menu’s [Built-in flash func. setting ] option. Select 
[ Flash exp. comp ] (p.149). 
  The exposure compensation ca n also be set with the [2 Expo. comp./
AEB ] menu (p.89).
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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 
compensation, AEB will be applied 
centering on the exposure 
compensation amount.
  Press < 0> to set it.
  When you press the shutter button 
halfway, the AEB amount will be 
displayed on the LCD monitor.
3Take the picture.
 Focus and press the shutter button 
completely. The three bracketed 
shots will be taken in this sequence: 
Standard exposure, decreased 
exposure, and increased exposure.
3  Auto Exposure Bracketing N
Standard exposure Darker exposure
(Decreased exposure) Brighter exposure
(Increased exposure)
AEB amount
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							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 shooting.
Press the shutter button three time s to take the three bracketed 
shots. The three bracketed shots will be exposed in the following 
sequence: Standard exposure, decr eased exposure, and increased 
exposure.
  Using AEB with exposure compensation.
Centering on the exposure com pensation amount, AEB will be 
applied.
  Using AEB with the self-timer or wireless remote control.
With the self-timer or wireless remote control (< Q> or < l>), you 
can take three continuous shots. With < q> set, the number of 
continuous shots will be three  times the number set (p.57).
Canceling AEB
Shooting Tips
 Neither flash nor bulb exposu res can be used with AEB.
  If the [ 2 Auto Lighting Optimizer ] (p.103) menu is set to other than 
[ Disable ], the AEB’s effect might be minimal.
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