How to stop the pre-flashes Nikon SB-910

dp19812003

I own a Nikon D600 and I'm trying to stop my sb-910 speedlight from doing the pre-flashes. Please help.

DenverShooter

Try turning off TTL.

Denver Shooter

clskelton

If you don't want to use manual on your flash, then assign a key on your camera to FV Lock or switch your SB-910 to A mode (not as accurate).

Also, if it is flashing four times or so then make sure your red-eye reduction flash is turned off on the camera. This was driving my crazy for a couple minutes one time.

Msmoto

Pp. 144, 145 of the manual…as noted the pre-flashes are the red eye reduction system working. To avoid this, use another flash sync mode. Probably front curtain is best for aver all purposes.

heartyfisher

Why do you want to turn off the preflash ? the pre-flash is what it uses to do the metering and all the TTL smarts. if you turn it off then you will need to set everything manually. the ISO, the aperture and the flash power..

Ade

As noted above, @dp19812003 probably meant "red eye reduction" instead of pre-flash.

Msmoto

OK, a question for those who have more knowledge.

Am I incorrect in thinking the flash output is determined by using both the AF focus system of the camera along with a red "pre-flash" from the flash unit itself?

And does not the camera have a small light which blinks to assist in AF performance? And, the final flash power output is determined by a combination of inputs?

Also, is there any feedback from the camera sensor itself to the flash so as to "shut off" the flash when enough light has hit the sensor?

I am looking to be educated on all this.. ….maybe this is why I always use available light…LOL

Ade

Both the red light on the flash and the small white light on the camera body are simply AF-assist lights. They are not used to determine flash power.

TTL works differently in film vs. digital bodies:

- In film cameras, the flash is fired until adequate feedback (reflection) from the film tells the flash circuit to shut itself off.

- In digital cameras, a series of rapid test flashes is fired before the shutter opens. Data from these test flashes are used to calculate the required flash power. The shutter then opens and the flash is fired at the calculated power without further feedback from the sensor.

The digital TTL test flashes occur in milliseconds and to our eyes indistinguishable from the actual flash exposure. They are often confused with the slow and deliberate flash pulsing visible in the "red-eye reduction" mode.

clskelton

The TTL pre-flashes can make some subjects blink. I usually catch my dog mid-blink even though her eyes were wide open when I pressed the shutter button. That's why FV lock is useful, so you can separate the pre-flash from the exposure flash. The SB-910 also has a light sensor for non-TTL Auto Aperture mode and will quench the flash once it determines enough light has reflected from the subject based on aperture/ISO settings the camera used.

TTL Pre-flashes will also trigger optical slaves too early, so if you're into using TTL with optical slaves for some reason then you could try one of the above options. I just use CLS or manual flash.

Ade

By default, the Auto flash modes (A/AA) also use pre-flashes, so simply selecting A/AA mode will not turn off the test flashes.

One can disable the A/AA pre-flashes via custom settings. However some functions are lost when pre-flashes are disabled (e.g., FV lock, white balance communications, and FP sync).

Msmoto

Thank you!