Built-in flash firing off even if I set it to OFF in the Commander panel

[ZapoTeX]

Hi everyone!

I have a D90 and a Metz 50 AF-1. I'm using the flash as a remote slave and, through the commander panel in the camera, I set Group A, Channel 1 to TTL and the built-in flash to off ("--" according to Nikon). I set the Metz to remote slave, Group A, Channel 1.

However, when I take a photo, if I don't extract the built-in flash from the camera, the Metz does not fire. If I extract the built-in flash, then both flashes fire.

Is this normal? I mean, I switched the internal flash to off, why does it fire? It actually fires so weakly that not a trace of it can be seen in the picture. However, I thought the communication between camera and flash happened through IR, not visible light.

Note: I did NOT set the Metz to Servo. It is simply remote slave. A proof of that is that the Metz does not let me choose "Manual" mode when I set it to slave, as it expects such decision to come from the camera. Also: if I use exposure compensation for Group A from the camera, the Metz actually does it. There is no doubt the camera and the flash are communicating digitally, but why would the built in flash fire???

Thanks everyone!

 

[ZapoTeX]

OK, I've done some more search and apparently it is normal:

Why is the D7000 commander mode flash firing during exposure when the manual says it won't? - Photography - Stack Exchange

That discussion is about the D7000 & SB-900, but it is exactly the same thing. At F4, ISO 200 I could not see any effect of the built-in flash, as it fires very weakly just for timing purposes.

Bye bye!

 

[Kombipete]

Hi everyone! I have a D90 and a Metz 50 AF-1. I'm using the flash as a remote slave and, through the commander panel in the camera, I set Group A, Channel 1 to TTL and the built-in flash to off ("--" according to Nikon). I set the Metz to remote slave, Group A, Channel 1. However, when I take a photo, if I don't extract the built-in flash from the camera, the Metz does not fire. If I extract the built-in flash, then both flashes fire. Is this normal? I mean, I switched the internal flash to off, why does it fire? It actually fires so weakly that not a trace of it can be seen in the picture. However, I thought the communication between camera and flash happened through IR, not visible light. Note: I did NOT set the Metz to Servo. It is simply remote slave. A proof of that is that the Metz does not let me choose "Manual" mode when I set it to slave, as it expects such decision to come from the camera. Also: if I use exposure compensation for Group A from the camera, the Metz actually does it. There is no doubt the camera and the flash are communicating digitally, but why would the built in flash fire??? Thanks everyone!

The flash from the built-in flash is the preflash communication between commander and slave telling it what you want the speedlight to do. These flashes won't affect the photograph because they happen before the shutter opens. So all is operating normally for you

 

[ZapoTeX]

Hi Kombipete,

thanks for your reply! Actually, in the picture in the Photo Exchange article both lights are visible. I've tested it myself and it is the same: I can see both flashes if I photograph a mirror. Anyway, in nearly any condition it does not bother.

Thanks again!