Nikon Coolpix 990 - Manual (Page 15)

programmable mode/function buttons. The command dial has been moved to the
top-rear of the camera and is easily operated with your thumb.
Note the "P*" -- the Coolpix 990 has a Flexible-Program mode. Rotating the command
dial lets you use different combinations of shutter speed and aperture.
The Coolpix 990 has TTL support for an external flash such as Nikon's SB-28DX shown
here on the SK-E900 flash bracket. The 990 has menu options for control of both the
internal and external speedlights, the internal can now be disabled while using an
external flash. It does not use the infrared focusing aid of the SB-28 or SB-28DX flash
units.