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Optional Flash Units (Speedlights)
The D90 can be used with CLS-compatible flash units. Remove the
accessory shoe cover when attaching optional flash units.
The built-
in flash will not fire when an optional flash unit is attached.
The Nikon Creative Lighting System (CLS)
Nikon’s advanced Creative Lighting System (CLS) offers improved communication
between the camera and compatible flash units for improved flash photography.
The Creative Lighting System supports the following features:
• i-TTL flash control: Improved through-the-lens (TTL) flash control for use with CLS
(see page 265).
Flash level is set using monitor pre-flashes to measure the light
reflected by the subject, ensuring optimal flash output.
• Advanced Wireless Lighting: Allows i-TTL flash control with remote wireless flash units.
• FV lock (pg. 198): Locks flash level at the metered value, allowing a series of
photographs to be taken at the same flash level.
• Auto FP High-Speed Sync (pg. 195): Allows the flash to be used at the highest shutter
speed supported by the camera, making it possible to choose the maximum
aperture for reduced depth of field.