1. Choose one of the manual exposure modes (PASM). Press the Menu button. Find the Custom Setting Menu and within this, choose the Bracketing/Flash option.
2. Scroll down until you see the Flash cntrl for built-in flash option. Select it.
3. Next, choose Commander mode which will present you with many different options on the screen. Because the pop-up flash is being used to trigger the speedlight that is off-camera, it needs to be raised in order for the wireless system to work. You do get the option of including the output of the pop-up flash in your exposure which you can set on this screen. In this example we want to have the flash fire, but not be included in the final exposure, so in the Built-in flash option on the menu, change the option to the two dashes, or off.
Then you will have the option of using groups for different flashes. Leave everything as it is: that is, Group A and B on TTL.
TTL stands for 'Through The Lens', which is Nikon's way to measure the flash exposure during the actual exposure of the image. Keep it on this setting so the camera does all the work for you, until you are comfortable with controlling more options on the flash itself.
Make note of the channel that the camera is firing on. By default, this is set to channel 1. Make sure to press OK to save selections rather than going back through the menus.
4. Pop up the flash on your dSLR -- don't forget this step otherwise your wireless system won't work!
5. Turn on the external flash unit and look for a remote option at the back. Select the remote option and make sure that the flash is set to TTL mode to match the camera.
6. Position the flash wherever you like, as long as the sensor at the front of the flash unit is within line of sight of the camera.
Your satisfaction is my priority; I hope I have earned 5 stars today!
Kindly take a moment to rate my service 5 stars and press Submit at the top of your question page to finish; tips appreciated :)
You can always reply back after rating me if you need any further assistance at all.