Canon IXUS 115 HS - Manual (Page 103)

103
You can make the main subject, such as people, appear bright by having the
camera provide the appropriate illumination with the flash. At the same time,
you can use a slow shutter speed to brighten the background that the light
from the flash cannot reach.
Choose ….
 After pressing the r button, press the qr
buttons to choose …, then press the m
button.
 Once set, … will appear on the screen.
Shoot.
 Even if the flash fires, ensure that the main
subject does not move until the shutter
sound ends.
Shooting with Slow Synchro
Attach the camera to a tripod to prevent the camera from moving and
blurring the image. Additionally, you should set the [IS Mode] to [Off] when
shooting with a tripod
(p. 175) .