By default, you can select one of 3 density levels (up to 6 stops in 2-stop intervals). If you enable the extended ND range, you can select one of 5 density levels (up to 10 stops in 2-stop intervals).
You can also perform this function remotely using Browser Remote on a connected network device.
 

Press the ND FILTER + or - button to select the desired ND filter setting. Repeatedly pressing ND FILTER + button will change the ND filter setting in the following order: [ND 2 stops] → [ND 4 stops] → [ND 6 stops] → [ND 8 stops]* → [ND 10 stops]* → ND filter off. (The ND FILTER - button cycles through the settings in reverse order.) The selected ND filter setting will appear at the bottom of the screen. * Only when MENU > [ Camera Setup] > [Extended ND Range] is set to [On].

NOTES If you set an assignable button to [ND +] or [ND -], you can press the button to change the ND filter setting. Depending on the scene, the color may change slightly when turning the ND filter on/off, Setting a custom white balance may be effective in such case. About the extended ND range: When you switch to or from a density level in the extended range (8 or 10 stops), you may notice one or both of the following circumstances. The focus may shift, affecting also the indication on the lens's focus distance scale. Depending on the lens, the camera may not be able to focus at infinity focus. Changing the ND filter setting using the optional RC-V100 Remote Controller: When the remote controller is connected to the camera, you can use the remote controller's ND button in the same way as the camera's ND FILTER + button. For settings between 2 and 8 stops, the corresponding ND filter indicator (1 to 4, respectively) will illuminate in orange. When the ND filter is set to 10 stops, indicators 1 and 4 will both illuminate.