1. Introduction
This manual provides detailed instructions for the proper use and maintenance of your Sekonic L-308B II Flashmate Meter. The L-308B II is a compact and lightweight exposure meter designed for both flash and ambient light measurements, offering versatile functionality for photographers.
2. Safety Information
- Do not expose the meter to extreme temperatures, humidity, or direct sunlight for extended periods.
- Avoid dropping the meter or subjecting it to strong impacts.
- Keep the meter away from strong magnetic fields.
- Do not attempt to disassemble or modify the meter. Refer all servicing to qualified personnel.
- Remove batteries if the meter will not be used for an extended period to prevent leakage.
3. Package Contents
Verify that all items are present in the package:
- Sekonic L-308B II Flashmate Meter
- Soft Case
- Strap
- Lumidisc
- Quick Guide
- (Battery not included, typically requires 1x AA battery)
4. Product Overview
Familiarize yourself with the components of your Sekonic L-308B II Flashmate Meter:

Image: The Sekonic L-308B II Flashmate Meter, showing its compact design, LCD display, and control buttons. The Lumisphere is visible at the top right.
- Lumisphere: Sliding dome for incident light measurement.
- Light Receiving Window: For reflected light measurement.
- LCD Display: Shows exposure values, settings, and battery status.
- MODE Button: Selects measurement mode (Ambient, Cord, Cordless).
- ISO Button: Sets film speed.
- MEASURE Button: Initiates measurement.
- POWER Button: Turns the meter on/off.
- Battery Compartment: Located on the back.
5. Setup
5.1. Battery Installation
- Open the battery compartment cover on the back of the meter.
- Insert one AA battery, ensuring correct polarity (+/-).
- Close the battery compartment cover securely.
5.2. Powering On/Off
- To turn on: Press the POWER button.
- To turn off: Press and hold the POWER button for approximately 1 second. The meter will also automatically power off after a period of inactivity.
5.3. Setting ISO Sensitivity
- Press the ISO button. The ISO value will blink on the LCD.
- Use the up/down arrow buttons (if present, or refer to specific model controls) to adjust the ISO value to match your film or camera setting.
- Press the ISO button again to confirm the setting.
6. Operating Modes
The L-308B II offers three primary measurement modes:
6.1. Incident Light Measurement (Ambient & Flash)
This mode measures the light falling onto the subject. It is ideal for determining overall exposure and achieving consistent lighting.
- Slide the Lumisphere into the extended position.
- Press the MODE button to select either AMBIENT (sun icon) or CORD/CORDLESS FLASH mode.
- Position the meter at the subject's position, pointing the Lumisphere towards the camera lens.
- Press the MEASURE button. For flash, trigger the flash unit after pressing the button (Cordless) or connect a sync cord (Cord).
- The LCD will display the recommended aperture and shutter speed.
6.2. Reflected Light Measurement (Ambient)
This mode measures the light reflected from the subject. It is useful for measuring specific areas or for contrast readings.
- Slide the Lumisphere into the retracted position, exposing the flat Lumidisc or light receiving window.
- Press the MODE button to select AMBIENT (sun icon).
- Point the meter directly at the subject or area you wish to measure from the camera position.
- Press the MEASURE button.
- The LCD will display the recommended aperture and shutter speed.
7. Maintenance
7.1. Cleaning
- Wipe the meter body with a soft, dry cloth.
- For stubborn dirt, lightly dampen the cloth with water or a mild cleaning solution. Do not use strong solvents.
- Keep the Lumisphere and light receiving window clean and free of dust or smudges to ensure accurate readings.
7.2. Storage
- Store the meter in its soft case when not in use.
- Avoid storing in areas with high humidity, extreme temperatures, or direct sunlight.
- Remove the battery if storing for extended periods.
8. Troubleshooting
- Meter does not power on: Check battery installation and ensure the battery has sufficient charge. Replace if necessary.
- Inaccurate readings: Ensure the Lumisphere/Lumidisc is clean. Verify ISO setting matches your camera/film. Ensure proper measurement technique (e.g., Lumisphere pointed correctly for incident light).
- Flash not triggering in Cordless mode: Ensure the flash unit is set to slave mode or optical trigger. Check distance and line of sight between meter and flash.
9. Specifications
| Feature | Detail |
|---|---|
| Model Number | 401308 |
| Measurement Modes | Ambient Light (Incident/Reflected), Flash (Cord/Cordless) |
| Light Receptor | Sliding Lumisphere (Incident), Lumidisc/Light Receiving Window (Reflected) |
| Power Source | 1x AA Battery (not included) |
| Item Weight | 5.6 ounces |
| Package Dimensions | 6.2 x 3.9 x 1.4 inches |
| Manufacturer | Sekonic |
| Date First Available | August 5, 2003 |
10. Warranty and Support
For warranty information and technical support, please refer to the warranty card included with your product or visit the official Sekonic website. Keep your purchase receipt as proof of purchase for warranty claims.
Manufacturer: Sekonic
Website: www.sekonic.com





