Nikon SPEEDLIGHT SB-16 - Manual (Page 37)

Example 2
If you are using ASA/ISO 400 film, the usable aperture is
now f/16 at At and f/8 at A2.
The auto shooting range varies according to the zoom
head setting as shown in the table. At the same zoom
head setting, the range is the same regardless of the film
speed and the corresponding f/stop available at At or A2.
As you can see in the table, the closest subject distance
is always 0.6m (2.0 ft.) except at the T setting of the
zoom head.
Note:
Regardless of the settings on the exposure calculator dial, any film
speed can be used for non-TTL automatic operation.