FEC for a nubie

Hi,
Newbie here. I just got my 430 EX II for my 60 D and I’m playing around with the FEC. If my camera and flash are in Manual mode, should I be able to adjust the FEC through the camera? Perhaps I’m mistaken but I thought could.

Flash is off camera.

Camera:
Manual
ISO 400
SS 1/250
Aperture 8.0

Flash:
Manual
1/8 power

I can’t seem to get the FEC to display or work. I thought I could dial in FEC through my camera and have I that setting customized to active when I push the button on the inside of the wheel. When I push the button, I get a screen that just says ‘M”. Any Ideas?
Thanks...

If the flash is in manual, FEC doesn't exist. Just like EC doesn't exist when the camera's exposure is set to manual.

Put the flash in ETTL mode. You can then adjust the FEC either in camera or on the flash itself.

Thanks Mike!!!

Like mike said FEC is for when the flash is in ETTL mode.

You use it to force the camera to expose properly (by telling it to tell the flash to put out more or less power then it thinks it should). The camera meter likes grey....it will try to expose white as grey and black as grey. So if you're in ETTL mode the camera is going to try and expose a beautiful white dress as grey (under expose) by telling the flash to put out less power then it actually needs to to make the dress white. To compensate you dial in +1 1/3 FEC (or whatever your flash/camera combo needs). Then the opposite holds true with scenes with lots of black in it like people in tuxedos. It's going to over expose so you dial in -1 1/3 FEC (or again what ever your combo needs)

When you're in manual you do not need FEC as you're the one telling the flash what power to output. So you simply raise or lower the power to suit.