3Custom Function SettingsNC.Fn II: Image
For 1 sec. or longer exposures, noise reduction is performed automatically if noise typical of long exposures is detected. This [Auto] setting is effective in most cases.
Noise reduction is performed for all exposures 1 sec. or longer. The [On] setting may be effective for noise that cannot be detected or reduced with the [Auto] setting.
After the picture is taken, the noise reduction process may take the same amount of time as the exposure. You cannot take another picture until the noise reduction process is completed.
With setting 2, if a long exposure is made during Live View shooting, the LCD monitor will not display anything (no Live View image display) while noise reduction is applied.
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.
With setting 1, continuous shooting and white balance bracketing cannot be used.