Nikon D2H D2H User's Manual - Page 122

Taking Photographs-Flash Photography D-TTL Flash Control D-TTL flash control is available when an optional SB-series 80DX, 28DX, or 50DX Speedlight is mounted on the camera accessory shoe. D-TTL flash control is not available with other optional Speedlights. The type of flash control depends on the lens attached: Lens Description 3D Multi-Sensor Balanced Fill-Flash for Digital SLR: Speedlight emits a series of nearly invisible preflashes (monitor preflashes) immediately before main flash. Preflashes reflected from objects in all Type G or D areas of frame are picked up by five-segment TTL flash control sensor CPU lens and analyzed in combination with information from matrix metering system to adjust flash output for natural balance between main subject and ambient background lighting. Not available when spot metering is used. Other lenses Multi-Sensor Balanced Fill-Flash for Digital SLR: As above, except that distance information is not included in regulating flash output. Precision of calculation can be increased for non-CPU lenses by providing lens data (focal length and maximum aperture; 124-127). Not available when spot metering is used. All types Standard TTL Flash for Digital SLR: Flash output is adjusted to ensure that main subject is correctly exposed, without taking the background into account. Recommended for shots in which main subject is emphasized at the expense of background details, or when exposure compensation is used. Standard TTL flash for digital SLR is activated automatically when spot metering is selected. 110