FEC and Powering up/down

[rebelmom1977]

I know this is a lame question, but is FEC when you're using ETTL the same as powering up/down when you're using the Manual mode of your speedlite? I'm confused because the increments are not the same.

Help a poor technically challenged girl out here ;-)

Thanks in advance!

~Jen

[Curtis N]

The FEC numbers, +1/3, -1, etc. refer to stops. +1 is one stop, or double the amount of light.

The power settings in manual mode change by one stop if you double it or cut it in half. 1/2 is one stop more than 1/4. I believe the 580EX can be adjusted in 1/3 stop increments.

[tim]

Curtis is right, but doesn't quite answer the question. FEC is only applicable when running in ETTL mode. In manual it does exactly what you tell it - ie power is 1/128th to 1/1 (ie full).

[roli_bark]

I'm confused because the increments are not the same.
~Jen

IMHO - In ETTL - the FEC levels you select are relative below or above the level determined automatically by ETTL. Whereas in Manual - the absolute flash level is under your control.

About increments - they can be set at both the Flash menu, and Camera menu. Your Flash 'User Manual' should tell which Increment setting overrides which.

[rebelmom1977]

Thanks for all your helpful responses!

~Jen