Powerful Flash for More Creative Freedom. The HVL-F42AM Flash Unit gives Sony system photographers more illumination power for every shooting opportunity, with effective range greater than 30 feet (10.5m), versatile bounce angles (90° up, 90° left, 180° right) and high-speed sync to catch fast action. It also provides intelligent features like auto zoom optimized for image sensor size, auto WB with color temperature signal to camera, and accurate ADI metering capability -- plus wide zoom angle (16mm) with retractable wide panel, simple controls, flash test button and fast recharging time to help you shoot more quickly (guide number: 42).