SB 800 pre flashes

[Spockman]

I have just got a SB 800 for my D1X. I use the camera in manual and want to use the TTL setting. In this mode (and all others as well) the flash keeps giving a number of pre flashes before the main flash? Why is this and how can I turn it off. Obviously some setting that is on that I am pulling my hair out trying to work out if its in the camera setting or the flash settings?

Cheers
Spockman

[gholmes1936]

Is that the "Red Eye Reduction" mode that is set in the camera?

[CJ Swartz]

You didn't mention what lighting setup you were trying to perform, but see if any of this info helps --

From the SB-800 manual -- "...The SB-800 fires a series of imperceptible Monitor Preflashes just before the flash fires to obtain information on the subject in these cases:
(1) when the SB-800 is used with cameras compatible with CLS, digital SLRs
not compatible with CLS, cameras in Group I with a CPU lens, and
COOLPIX cameras compatible with i-TTL, and flash mode is set to TTL
auto flash, and (2) when the SB-800 is used with cameras compatible with CLS with a CPU lens, and the flash mode is set to Auto Aperture flash.
Monitor Preflashes are fired instantaneously and cannot be differentiated from the main flash, but H appears on the LCD panel (using a single flash unit).
However, for cameras in Group I, Monitor Preflashes are not fired when the
SB-800’s flash head is adjusted to other than the horizontal/front or down to –7° position, or the camera’s flash sync mode is set to Rear-curtain sync, even when H appears on the LCD panel.

The commander works by sending information to the slaves via pulses of light, kind like a fast version of Morse code. The camera waits for the "handshake" to end and then trips the shutter again and exposes for that flash. Hence the term pre-flash.

Also, from DPreview.com forum discussion "...The commander works by sending information to the slaves via pulses of light, kind like a fast version of Morse code. The camera waits for the "handshake" to end and then trips the shutter again and exposes for that flash. Hence the term pre-flash..."

This DPreview discussion is long and convoluted, but it does finally explain how to set your camera to avoid pre-flashes so you can avoid them setting off your other strobes -- "...Set your function button to pre flash. Push it, the pre flash will fire to meter the lights, it will also set off your strobes. Now it will hold the settings for you, no more pre flash. Your flash will fire normally now. If you have to adjust, push the function button again to cancel...."