580EX-II Auto-firing

[Edgar]

I have some weird experiences with the speedlite the other day where it was firing a series of flashes on its own for no reasons.

The camera was set on Program mode and I had just finished taking a shot when the speedlite decided to fire on its own.

I switched if off instantly and powered it back on and it's fine again. The same thing happened before and this was the second time I have such experience.

The series of flashes behaves like the camera's built-in flash auto-focus assist lamp. Was there any particular reason why the speedlite would do that?

[ricktas]

I know some one who has a Nikon SB800 that does the same. Just occasionally gets a mind of its own and triggers itself. Don't know the answer, but wanted to post so that people understand that its not a Canon only issue.

[jev]

Does that happen when the flash is still attached to the camera? If so, you could have touched the button on the front of the camera usually used for checking aperture with (the flash than fires a series of "modelling flashes"). Or it could be it is making and breaking contacts on the hotshoe - if there is tolerance in the mechanical attachment of the hotshoe this can happen too.

[Edgar]

Yes it happens the the fflash is still attached to the camera. It does that on its own even when I am just holding the camera.

I was also thinking that it would be some issues with the contacts, but I gave it a very gently nudge just then and doesn't seem to behave as such, as the locking mechanism on the hotshoe are very secured.

[N*A*M]

The series of flashes behaves like the camera's built-in flash auto-focus assist lamp. Was there any particular reason why the speedlite would do that?

FV lock button? flash might be doing the preshot metering sequence