For those photographers ready to flash, we salute you. Flash with an extra burst of light, that is. The HVL-F20S is an external flash unit that is compatible with any of the NEX cameras — with the exception of the. It's bigger and much more powerful than the included clip-on flash for the NEX cameras. It sits in the proprietary hotshoe mount, drawing power from the camera itself rather than via any batteries of its own. Sony claims it reduces the overall battery life of the camera (according to its CIPA rating) by around 20 per cent when in use. For example, the battery life of the NEX-C3 would be reduced to 320 shots rather than 400 shots when the flash is in use.
The F20S screws into place with a small, rotating dial at its base. There's only one shooting angle to choose from, tilted up 75 degrees. Another unfortunate design issue is that the flash unit doesn't swivel around its base to give directional light. It can be bounced upwards by rotating the ring on its side for bounce flash. Also provided in the box is a small wide converter attachment that clips on the front of the flash unit to broaden how far the light is thrown.
There's no external dials on the F20S to adjust anything, including power or flash intensity. Controlling the flash compensation has to be done through the camera menus, and turning the flash on and off is done by raising and lowering the head.
Sony doesn't recommend the use of Alpha lenses with this flash unit, attached via the E-mount to A-mount adapter. We didn't have any Alpha lenses to test this, but Sony claims the larger lenses can block the flash throw, darkening the lower part of the image.