www.sigma-imaging-uk.com Rather than using two semicircular flash tubes that encircle a lens, Sigma’s offering contains two fairly small straight tubes on opposite sides of the circular flash head. In theory this doesn’t make for the softest results, but in practice its light is only marginally harsher than the Nissin’s, while TTL exposure metering and colour rendering are pretty accurate.
The flash is controlled by a bulky commander unit that resembles a flashgun. Build quality is good, but the plastic hotshoe mount is disappointing. The fiddly, dated controls and unintuitive display also take some getting used to.
There’s no shortage of features, though. You get a modelling/AF-assist lamp, wireless TTL flash control and high-speed-sync capability, plus independent output adjustment for each flash tube from the max guide number of 14 down to 1/64 power.
The flash comes bundled with 55mm and 62mm lens adaptors, with additional sizes up to 77mm available separately.