So I borrowed a flash from a friend because I need an extra light for something I want to shoot.
I'm shooting off camera, full manual, etc...
I know the obvious stuff, set it to M mode, set the power and zoom.
I know where the menu items are to turn on/off the optical slave mode.
What is stumping me at the moment is the F{x} setting next to the zoom settings. Coming from using canon 580ex II, canon 540ez and lumopro 160 in manual mode, I've never encountered this on a speedlight.
Is it of any use in manual mode, does it do anything?
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