Canon RebelT3I EOS 600D Instruction Manual page 55

Custom Function Settings*
Reduces the noise generated in the image. Although noise reduction is
applied at all ISO speeds, it is particularly effective at high ISO speeds. At
low ISO speeds, the noise in the shadow areas is further reduced. Change
the setting to suit the noise level.
O: Standard
1 : Low
2: Strong
3: Disable
With setting 2, the maximum burst for continuous sh0eting Will greatly
decreasel
#_ Jfy0u playback a _ or i_r_4-d L image With the Camera or print an
image directly, the effect of the high ISQ speed noise reduction may look
minimak You can check the noise reduction effect or print naise-reduced
images with Digita! Photo Pi_ofessiona! (provided saftware, p.302),
O: Disable
1 : Enable
Improves the highlight detail. The dynamic range is expanded from the
standard 18% gray to bright highlights. The gradation between the grays
and highlights becomes smoother.
_ With Setting il the Aut0 Lighting optimizer (P1!09)iS automatiCallY Sett0
[Disab!e] and the setting cannot be changed:
® With Setting ii noise may become Slightly more pronounced than with
setting O.
With Setting i, the seitable range will b e Jso 200 _ 6400.
Also, the <De-> icon will be displayed On the LCD monitor and in the
viewfinder when highlight tone priority is enabled,
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