Hi Serge,
There is no magnet on the Z240, so I'm assuming you are talking about the pre-flash mode switch, the button on the bottom-right, just below the power dial.
My setup is an EOS50D and two Z240 (one Type 2 and one type 3). I set both of them on "Push" position ; both flashes are obviously in Manual mode, and everything works fine.
davirond
Member Since 06 Dec 2007Offline Last Active Apr 26 2013 12:24 PM
