Canon EOS REBEL T6i Instruction Manual page 138

3 Setting Noise ReductionK
When [Multi Shot Noise Reduction] is Set
If there is significant misalignment in the image due to camera shake, the

noise reduction effect may be minimal.
If you are handholding the camera, keep it steady to prevent camera

shake. Using a tripod is recommended.
If you shoot a moving subject, the moving subject may leave

afterimages.
The image alignment may not function properly with repetitive patterns

(lattice, stripes, etc.) or flat, single-tone images.
If the subject's brightness changes as the four consecutive shots are

taken, irregular exposure in the image may result.
It takes some time to record images to the card since noise reduction is

applied and the images are merged after shooting. During the
processing of the images, "BUSY" will be displayed, and you cannot take
another picture until the processing is completed.
1+73 or 1 cannot be selected. AEB and WB bracketing cannot be

used. [z3: Long exp. noise reduction] cannot be set. If any of these
has already been selected or set, [Multi Shot Noise Reduction] cannot
be set.
The [Distortion] setting will be set automatically to [Disable].

Flash shooting is not possible. The AF-assist beam will be emitted

according to the [54: Custom Functions (C.Fn)]'s [4: AF-assist beam
firing] setting.
You cannot set [Multi Shot Noise Reduction] for bulb exposures.

If you turn off the power, change the shooting mode to a Basic Zone

mode, shoot a bulb exposure, or shoot a movie, the setting will
automatically be changed to [Standard].
[z3: Dust Delete Data] cannot be set.

Long Exposure Noise Reduction
Noise reduction is possible with images exposed for 1 sec. or longer.
138
Select [Long exp. noise
1
reduction].
Under the [z3] tab, select [Long

exp. noise reduction], then press
<0>.