Nikon 25215 manual 107, SB-800, SB-600 i-TTL Flash Control

TTL Flash Control

TTL flash control is available only with optional SB-series 800, 600, 80DX, 28DX, and 50DX Speedlights.

SB-800, SB-600: i-TTL Flash Control

When the SB-800 or SB-600 is set to TTL, the camera automatically selects one of the following types of flash control:

i-TTL Balanced Fill-Flash for Digital SLR: Speedlight emits series of nearly invisible preflashes (monitor preflashes) immediately before main flash. Preflashes reflected from objects in all areas of frame are picked up by five-segment TTL flash control sensor or 1,005-pixel RGB sensor and are analyzed in combination with information from matrix metering system to adjust flash output for natural balance between main subject and ambient background lighting. If type G or D lens is used, distance information is included when calculating flash output. Precision of calculation can be increased for non-CPU lenses by providing lens data (focal length and maximum aperture; 128–131). Not available when spot metering is used.

Standard i-TTL Flash for Digital SLR: Flash output adjusted to bring lighting in frame to standard level; brightness of background is not taken into account. Recom- mended for shots in which main subject is emphasized at expense of background details, or when exposure compensation is used. Standard i-TTL flash for digital SLR is activated automatically when spot metering is selected.

Taking Photographs—Flash Photography

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