The pocket size of Nissin i40 weights only 203g of weight. It is suitable for filling shadows on even the sunniest of days, suitable for family shooting, indoor/ outdoor shooting and especially suitable for traveling. Professional functions are included: Wireless TTL mode; Supports up to 1/8,000 seconds shutter speed; Flash output of GN40 at 105mm; Video light function with 9 steps of output level adjustment; Simple operation panel with two selector dials to operate the flash; Flash head tilts up and rotates horizontally to right and left for making bounced lighting more versatile by utilizing more angles. A Soft box is supplied. Additional features: Slave Modei40 has a wireless remote flash system as a slave unit. You can enjoy creative flash photography with multiple lightings from the various directions. There are 3 slave modes provided. Slave Digital (SD): i40 synchronizes to the pre-flash system. The master flash is to be set at TTL (E-TTL for Canon, i-TTL for Nikon and ADI/ P-TTL for Sony) mode. Slave Film (SF): i40 synchronizes to the traditional single flash system. The master flash is to be set at manual mode. Studio lighting system synchronizes to this mode. This mode is also available for open flash, and for a standard flash in the market. Wireless TTLi40 synchronizes to the wireless remote flash system. TTL FLASH LEVEL COMPENSATION The power of the flash can be controlled with TTL flash level compensation. Whereas total exposure is controlled by the camera's EV compensation function, the flash can compensate for the exposure on the main subject only, with little impact on the exposure of the background scene. The flash power level can be adjusted from -2EV through +2EV by 0.5EV steps.