Output. The Sony HVL-F28RM External Flash has a guide number of 92 feet at ISO 100 and 50mm with the ability to produce around 110 full-power flashes on a fully charged set of batteries. This flash uses four AA batteries (not included).

Built-In Transceiver. This flash is equipped with a 2.4 GHz transmitter, meaning that it can function as a radio commander or remote as part of Sony’s radio wireless system. It has a 115-foot operating range and doesn’t require line of sight. It’ll support fifteen flashes in five groups on one of fourteen channels. It’s fully supported by Sony’s P-TTL/ADI metering system, including high-speed sync and ratio control.

Bounce and Zoom. You can tilt the HVL-F28RM from 0° to 120° for full bounce-flash capability. It has a 50mm focal-length field of view, which you can expand to 24mm with a pull-out diffusion panel.

Advance Distance Integration Flash Metering. The Advance Distance Integration flash metering system takes camera-to-subject distance into account in order to more accurately balance flash strength with ambient light and the light falling on a subject’s face when you’re working with cameras and lenses with distance encoders. This renders your subject with natural, lifelike color.