Nikon SB 14 - Manual (Page 22)

Open-Flash Button @
The red open-flash button is used to fire the flash unit
manually without having to trip the camera's shutter. In
this manner, you can create multiple-exposure "strobo­
scopic" effects or paint the scene with light by firing
the flash repeatedly with the camera set to "B." However,
with the SB-14 connected via a sync cord to the camera
set at "B," the flash will not go off even when the open-
flash button is pushed. So, make sure to remove the con­
necting cord from the camera before using the open-
flash button.
The open-flash button is also used in conjunction with the
ready-light to determine if you can get the correct ex­
posure when shooting on automatic. This is especially
useful when doing bounce flash. After setting up the shot,
push the open-flash button. If the ready-light does not
blink, you can take the picture. If it does blink, try
moving the flash closer to the subject or bounce surface.