D90-Sb600 help I have set my nikon d-90 to "--" and channel A in commander mode. i dont want my on camera flash to flash but it still does. My flash setting are the same. What can i do?

To use the flash in commander mode the "pop-up" flash still has to emit the triggering/control pulse to cause your Nikon flash to fire. With the camera set to "--" mode the flash still fires but the flash does NOT provide a large enough output to provide any exposure. The "flash" only provides the "trigger pulse", to enable your SB-600 to fire.

The only way to prevent any kind of flash in Commander Mode would be for you to purchase an Nikon SU-800 Command Unit, this is effectively a flash with out a "flash tube" , but it does the same job as the "infra red" section of your SB-600.

Hope this helps
Cheers
Ian561

The on-camera flash has to flash if you want it to be in commander mode. That's how it sends commands to slave flashes. Set to "--", that's all it does, the flash will not affect the picture.

If you want to operate remote flashes without any flash from the camera, you'll need to invest in a third-party wireless commander and triggers.