Top features:- Works with the E-TTL II flash metering system for accurate exposure - Ratio control across two groups of flashes for creative results - High-speed sync lets you shoot at wider apertures - Indoor range up to 15 m and outdoor range up to 10 m Works with the E-TTL II flash metering system The Speedlite ST-E2 allows you to control a wireless flash directly from the camera. Working with the Canon E-TTL II flash metering system, it ensures accurate exposures that are consistent in all types of shooting conditions. In situations with complex lighting conditions, the transmitter makes use of exposure compensation to give you more control over light output to capture the ideal image.Ratio control across two groups of flashesYou can control the ratio of light output over two groups of flashes simultaneously. Adjust the ratio between 1:8 and 8:1 for both groups allows you to capture creative results which are certain to impress. High-speed sync In bright daylight, you can shoot at wide-apertures using faster prime lenses thanks to high-speed sync. This allows you to sync the flash at shutter speeds faster than the maximum sync speed of the camera, offering greater control and versatility when it comes to capturing the perfect shot. When shooting in low light conditions, the transmitter can emit a focusing beam which covers all of the focusing points on EOS cameras. This feature ensures sharp results in your images even when ambient light is a factor. Indoor range up to 15 m and outdoor range up to 10 m When shooting inside, the Speedlite ST-E2 has a working range of between 12 m and 15 m, making it easy to capture your subject from a variety of angles and positions. You can also shoot with confidence outside, with a working range between 8 m and 10 m.