Triggering 7D ETTL preflash with * button

Using the* button to trigger the preflash doesn't seem to work. My 20D/40D works fine with any flash, but my 7D doesn't work with any flash. Anyone know what's up? I couldn't find any menu or custom function where it can be enabled/disabled.

You do that with M-Fn button

I read the manual and found most of the answer. The M-Fn button does does the flash exposure lock, and the * button does the exposure lock. On the 20D-40D the * button was FEL.

Using CF IV-1 you can reassign FEL back to the * key. I kinda wish the one key could do both, or change to FEL automatically if you're in manual mode. I just want to have an easy way to lock flash exposure as the ettl preflash causes lots of people to blink.

On the 40D I thought a shutter half press locked focus and exposure, but I suspect i'm wrong on that.

Edit - thanks Cicero, I posted at the same time as you

tim wrote in post #8884763
I read the manual and found most of the answer.

You ought to have a price, if there is any, for doing that before somebody writes RTFM.
On the 40D, the * button is AE lock (unless you swap it with AF-ON). It's just when you put on a flash, you can't do AE lock any more (well, there is a trick, but not normally). The 7D does this in the same way as the 1D series, i.e. keep AE lock on the * button and FEL on the button beside the trigger. Unless you customize them away, they are both always there, ready to be used.

On the 40D, a shutter half press locks focus and exposure, provided you are using evaluative metering and One Shot AF. Otherwise, it does not. But that's the same with the 7D. Again, it can be changed on both of them.