A company called Pixel
and located in Shenzhen, China has just launched radio triggers that it calls “wireless TTL cords” and that it
claims is compatible with the TTL of Nikon's and Canon's dedicated flash
systems.
TR-332 transmitter and receiver. Photo: Pixel.
The units are known as as
TR-331 (Nikon), and
TR-332 (Canon).
Details are sketchy at the moment, and the “English” text
on Pixel's home page is machine translated gibberish that does not
make much sense. However, according to the specifications, it
communicates on the 2.4 GHz frequency (unregulated worldwide),
provides 15 selectable channels, and works at distances between transmitter
and receiver up to 65 meters. The units uses CR-2 3 V lithium
batteries (2 in the transmitter, 1 in the receiver),
Users report that the units are compatible with TTL, but that the “cord”-reference should be taken literally. They are replacements for an off-camera flash cord, not for the the light-based systems that Canon and Nikon use to control several remote flashes wirelessly.
One source of information about these units is
this thread
in the strobist group on Flickr. Some of the early adopters hang out there.
As for pricing, the units typically sell on eBay for USD 206
for a transmitter/receiver pair,
with USD 120 for each additional receiver.
However, if you can manage without TTL, USD 30 will get you a nice poverty wizards kit.