Lightweight and compact, the EF-140S Electronic Flash from Sigma is optimized for use with the DP Quattro camera line but is compatible with cameras featuring Sigma's S-TTL. The hot shoe-mounted flash has a guide number of 46' at ISO 100 for providing additional illumination in low-light scenarios. The flash will offer coverage for a 19mm lens in the APS-C format and it has a recycle time of approximately 5 to 6.5 seconds. Slow sync and red eye reduction modes are available for more control over the lighting effects as well as more manual control over output via the in-camera controls. This includes flash exposure compensation from -3 to +3 EV in 1/3 EV steps. Also, on the rear of the flash is an LED that will indicate when it is ready to fire. Included with the flash is a drawstring carrying pouch and it will run on 2 AAA batteries. Exposure compensation can be done in camera form -3 to +3 EV Flash range of 3.3-16.4' at ISO 100 or 3.3-131.2' at ISO 6400 Manual control is possible through in-camera controls Weighs just 2.4 ounces Note: Sigma EF-140S is not compatible with Sigma dp0 Quattro