Sekonic L-858D-U SPEEDMASTER Light Meter with RT-GX Transmitter

The Sekonic L-858D-U SPEEDMASTER is a professional light meter designed for photographers and cinematographers who demand precise exposure control. It measures both ambient and flash light, supports incident and reflected metering modes, and provides a comprehensive suite of tools for evaluating lighting conditions. What elevates this particular bundle is the included RT-GX transmitter module, which gives the meter full radio control over Godox flash systems. From the meter itself, you can trigger flashes, switch between channels and groups, and adjust modeling light power — eliminating the need to walk back and forth to your lights during setup.

One of the L-858D-U's most notable capabilities is its HSS (High-Speed Sync) flash measurement, which accurately reads flash power at shutter speeds above the camera's native sync speed — a feature that many meters lack entirely. The flash analysis function goes further by providing detailed breakdowns of flash characteristics, giving you data on flash duration and performance that is invaluable for freezing motion or matching multiple flash units. Measuring 6.93 x 3.7 x 1.93 inches and weighing one pound, the meter is solidly built and designed for professional field use. For anyone working regularly with Godox lighting and needing reliable, advanced metering, this combination of the L-858D-U and RT-GX transmitter represents one of the most capable handheld lighting control solutions available.