Olympus STYLUS 1s Instruction Manual page 41

ND Filter Setting
Select [On] to reduce the light entering the lens. Photograph running water at slow
shutter speeds or use wide apertures in bright light.
1
Press the Q button to display the live control, and select the ND filter
item using FG.
2
Use HI to select an option and press Q.
Off The ND filter is not used.
On The ND filter is used.
4
EN 41