The compact HVL-F20M External Flash from Sony is an ideal choice for use as a small fill light or as a wireless TTL controller for off-camera flash units. Supporting the use of the ADI / P-TTL system, it is compatible with Sony's Multi Interface shoe. It offers a guide number of 66' / 20 m at ISO 100 and 50mm along with two coverage settings for 27mm or 50mm with full-frame sensors. The head can tilt between 0-75° for bounce flash and gives you great control over the direction of the flash. A built-in diffuser helps to control the spread of light from the flash and features wide and tele flash settings to suit your needs.
It is not natively compatible with the older Sony/Minolta Auto-Lock Accessory Shoe, though with the use of a separately available ADP-AMA Shoe Adapter, Sony cameras with the Auto-Lock Accessory Shoe can be adapted to use Multi Interface Shoe external flashes with full compatibility. Advance Distance Integration (ADI) flash metering works with cameras and lenses with distance encoders to more accurately balance flash output with ambient light and subject reflectivity by taking camera-to-subject distance into account.
For remote triggering of additional off-camera flash units, the HVL-F20M is able to work as a TTL controller. It has slow, first and second curtain sync settings and will recycle in 0.1 to 5 seconds. It runs on 2 AAA batteries and comes with a terminal protector cap and a carrying case. Turn the flash on or off by simply raising or lowering the flash unit. The HVL-F20M has a battery life of approximately 90-150 flashes.