Did you try to use external flashes with the NEX 7 ?
I'm a beginner with Sony flash system and not so familiar yet with radio based wireless flash trigger.
I bought the Sony HVL F58AM Flash
Coming from the Nikon world I assumed that other manufacturers would also enable the fact you can trigger your external flash with the embedded one... MISTAKE!
You need actually to put a sony flash, anothe one... on the Nex 7 Hot Shoe in order to trigger the external flash with TTL functionality.
even having shot sony for many years this is surprising. Before switching to A850(no in body flash) I had an A700 that was able to provide commander flash functionality.
It seems strange that they wouldnt include it on their "high end" NEX. I guess you will have to hope for firmware updates or a newer "more high end" model to be released.
Interestingly the NEX-7 is one of the very few Sony/Minolta bodies with wireless TTL capability and no way to trigger without an external flash. Wireless command with a RTF was a Minolta innovation, they had it a decade before anyone else (introduced on the 7xi around 1992-3)
Note the HVL-F20 flash can command despite being the cheapest iISO Sony flash. It's intended as a RTF-replacement for the A900/A850 and thus has command capabilities.
I think it's a good product but it's still pretty big.
Today we can put Bluetooth chips and Wifi chips into a smartphone so why couldn't we find an apple ipod shuffle size-like device in order to replace classic big flash triggers, it would be so nice to put in the bag and plug in the Nex 7 hot shoe. It would fit the camera size for sure.
Why, why, why did Sony decide to put a hotshoe that needs an adapter to function with any standard hotshoe device? Instead we're forced to buy an adapter. So frustrating since they ticked most of the boxes for what a compact camera should have feature-wise. I would love to just drop my Cactus triggers on the Nex7 and fire away without adding another $150 piece of plastic on to my camera. Its keeping me from adding one to the arsenal. I hate buying proprietary accessories like this that will probably disappear they add a real hotshoe to the Nex7n. I had a Sony video camera and you needed a special cable to connect a mic, lose the cable and you're out $100 for a replacement - I lose two of them over the life of the camera and they were difficult to find anywhere in stock, including the Sony store. Grrr...