In my experience when you mix brands you have to experiment with different
settings: ISO, manual, automatic, etc.
It is not always a straightforward matter of sticking any auto flash on any
digital camera and having it work properly even if the camera manual says it
should. This has been my experience with hi end Sony digital cameras.
Even within brand lines older auto flashes made for film cameras may not
work in a straightforward fashion on digital cameras. This has been my
experience with Nikon dSLRs and older flash units.
>> Stay informed about: Panasonic FZ20 and Nikon speedlights