I looked in the manual to refresh my knowledge. I remember that at the beginning I had the same problem as you. Here is what the manual says :
Shooting still pictures in a higher resolution (High Res Shot) (p. 60)
When shooting an unmoving subject, you can shoot pictures in a higher resolution. A
high resolution image is recorded by shooting several times while moving the imaging
sensor. Please shoot with the camera fixed to a tripod or similar.
You can change the time between the shutter button is pressed all the way down and
the shutter is released in [High Res Shot] in X Shooting menu 2. Set to [Off] to hide
this setting item (P. 95). After setting high resolution shot, you can select the image
quality of the high resolution shooting using image quality mode (P. 61).
1 Press the Q button to select j/Y (sequential shooting/self timer).
2 Select h using the front dial and press the Q button.
3 Shoot.
• If the camera is unstable, h will blink. Wait for the blinking to stop before shooting.
Cautions
• Image quality is fixed to LF.
• When image quality is set to RAW+JPEG, the camera saves a single RAW image
(extension “.ORI”) before combining it into a High Res Shot. Pre-combination RAW
images can only be played back on the software that comes with this camera.
• When shooting under fluorescent lighting etc., image quality may deteriorate.
• [Image Stabilizer] is set to [Off].
Selecting image quality (still image quality mode) (p. 61)
After setting High Res Shot (P. 60), you can select between LF and LF+RAW.
Setting hi-res shot (High Res Shot) (p. 95)
When you set hi-res shot, the items will be marked with h in sequential shooting/self
timer mode (P. 58).
1 Select [High Res Shot] in X Shooting Menu 2.
2 Select the item you wish to set.
High Res Shot Sets the time period between the shutter button being pressed
all the way down and the shutter release when shooting in hi-res
shot mode. When this time period is set, h will be displayed in
sequential shooting/self timer mode. When not using hi-res shot,
set to [Off].
#Charge Time Sets the time to wait for the flash to complete recharging when
using a flash other than the dedicated flash that is supplied.
Hopefully that will help somewhat.