Radio transmitter Sekonic RT-GX for L-858D (model 012069) — wireless flash triggering accessory

The Sekonic RT-GX radio transmitter is an optional wireless flash triggering accessory designed to work with the Sekonic L-858D light meter. It connects to the meter to enable remote triggering and basic control of compatible flashes and lighting units, streamlining flash testing, synchronization and exposure verification during studio and on-location shoots. The compact transmitter integrates with the meter’s workflow to provide hands-free flash operation and faster setup when working with multiple lights or when the photographer must be away from the camera.

Advantages

The RT-GX provides reliable radio triggering without line-of-sight constraints, improving flexibility in lighting placement. Integration with the L-858D enables synchronized measurements and remote flash testing directly from the meter. Its compact design and simple mounting make it easy to add to existing setups, reducing the need for separate triggering devices and speeding up workflow in both studio and location environments.

Suitable for

• Studio flash testing and synchronization
• On-location portrait and commercial shoots requiring remote flash control
• Multi-light setups where hands-free triggering accelerates measurement and adjustment
• Situations that require remote exposure verification and flash recycling checks

Key specifications

• Wireless radio transmitter compatible with Sekonic L-858D
• Enables remote triggering and basic control of compatible flash units
• Compact, lightweight form factor for easy mounting
• Designed for use in studio and on-location workflows

How to use

Attach the RT-GX transmitter to the compatible port on the L-858D light meter according to the meter’s instructions. Position the transmitter so it has a clear radio path to the flash units when possible, then pair or sync with compatible flashes following Sekonic’s pairing procedure. Use the meter to trigger flashes remotely and perform exposure checks and synchronization tests; adjust flash output or placement as needed based on meter readings. Follow safety guidelines for flash use and ensure batteries or power sources for both meter and flashes are charged before shooting.

Recommendations

For consistent results, test radio triggering range and latency in your actual shooting environment before a session. When working with multiple wireless systems, verify channel and group settings to avoid interference. Keep firmware on the meter and flashes up to date and consult Sekonic documentation for compatibility details.