Nikon N90 AF Instruction Manual page 116

SHUTTER SPEED/APERTURE FOR EACH EXPOSURE MODE IN TTL AUTO FLASH
When setting shutter speed and aperture, refer to the following
table.
Camera's exposure mode Shutter speed
If focal length in use is 60mm or shorter: 1/250 sec.
to 1 I(focallength)
sec: 1
Programmed Auto (P, Ps)
If focal elngth in use is longer than 60mm: 1/250
sec. to 1/60 sec: 1
Shutter-Priority Auto (5)
Manually set as desired from 1/250 sec. to 30
sec: 3
If focal length in use is 60mm or shorter: 1/250 sec.
to 1 I(focallength)
sec: 1
Aperture-Priority Auto (A)
If focal elngth in use is longer than 60mm: 1/250
sec. to 1/60 sec: 1
Manual
(M)
Manually set as desired from 1/250 sec. to 30
sec: 3
'1 With Slow Sync or Rear-Curtain Sync, automatically controlled shutler speed range is extended down to 30
sec.
'2 Available maximum aperture depends on film speed in use. See chart on next page.
'3
If you set shutler speed at 1/500 sec. , or faster, camera automatically shifts to 1/250 sec. , as soon as
Speedlight is turned on.
116
Aperture
Set lens to its minimum aperture. Aperture is
automatically controlled between f/2.8 and lens
minimum aperture' 2
Manually set as desired