Specifications:

Dimensions: 28mm (W) × 29mm (L) × 13mm (H) (excluding the hot shoe foot)

Metering Angle: 30° (non-circular, ±15° left/right, +12° up, -15° down)

Metering Sensor: Vishay VEML7700 (meets CIE standard for human eye spectral sensitivity)

Metering Range: EV0–EV19 (at ISO100)

ISO Range: 12–6400 (in 1/3-stop increments)

Metering Modes: Aperture Priority, Shutter Priority

Parameter Ranges:

Aperture Priority: Aperture: f/1.0–f/64 (½-stop increments), Shutter Speed: 1/2000s–1s (½-stop increments)

Shutter Priority: Shutter Speed: 1/2000s–30s (full-stop increments), Aperture: f/1.0–f/64 (½-stop increments) (Note: Reference ISO international standards and GB national standards. Marked values may differ from actual calculated values; e.g., 1/125s is actually 1/128s.)

Exposure Compensation: -9.9 EV to +9.9 EV

Exposure Calibration: -9.9 EV to +9.9 EV

Power Supply: 150mAh Lithium Battery, USB Type-C Charging

Battery Life:

Standby current: 10μA

Operating (full brightness): <5mA

Operating (50% brightness): <2mA

Auto sleep/standby mode enabled

Operating Instructions:

In sleep mode, press the "Metering" button to wake the device.

Short press the "Metering" button for single measurement; long press for continuous measurement.

Use the "+" and "-" buttons to adjust settings.

Press the "Set" button to cycle through the following menus:

ISO: Set ISO sensitivity

MODE: Select metering mode (Aperture/Shutter Priority)

COMP: Set exposure compensation

CAL: Set exposure calibration (Note: The bottom-right corner of the "CAL" screen displays the current battery voltage in mV.)

In any settings menu, press the "Metering" button to return to the measurement screen.

The device will not auto-sleep while in a settings menu. On the main measurement screen, the display will automatically turn off after approximately 20 seconds of inactivity.

Battery & Charging Indicators:

"L" appears when battery is low.

"C" appears when charging via USB cable.

"F" appears when fully charged.

If the battery is too low, the screen cannot be woken — please charge immediately.

When exposure compensation (COMP) is not zero, the measurement screen will display the compensation value instead of the actual EV value, to prevent accidental use with unintended settings.

Error & Troubleshooting:

If the display shows the number "1", it indicates the microcontroller has restarted due to an error. This typically occurs due to communication failure between the microcontroller and the sensor or display. Such events are rare. After restart, the device will function normally, but all user settings (ISO, Mode, COMP, CAL) will be reset to default values.