Sekonic Flashmate L-308X Light Meter (Exposure Meter). The Sekonic L-308X Flashmate is a compact and accurate light meter for photographers and filmmakers. It measures both flash and ambient light and offers dedicated modes for still photography, HD video and professional cinematography.
The L-308X helps you quickly determine the correct exposure by measuring either incident light at the subject or light reflected from the subject. Its clear LCD screen displays the selected settings and measured values in full, half or third stops. When set to full-stop increments, the measured value is also displayed with an accuracy of 0.1 stop.
- Measures flash and ambient light
- Designed for photography, HD video and cinematography
- Incident and reflected light measurement
- Photo, HD Cine and Cine modes
- Accurate measurement in 0.1 EV increments
- Compact and lightweight design
- Powered by a standard AA battery
Measure incident or reflected light
For portraits and other three-dimensional subjects, the spherical Lumisphere diffuser is normally used to measure the incident light at the subject. This method provides a reliable exposure reading regardless of the subject’s colour or reflectance.
For reproduction photography of paintings, documents and maps, the flat Lumidisc diffuser can be used. It is also suitable for measuring contrast, checking light distribution and evaluating the exposure range of a scene. The Lumidisc is available as an optional accessory.
The L-308X can also measure light reflected from the subject. The Lumisphere slides to the side, allowing the built-in sensor to be pointed towards the subject. The measuring angle is approximately 40°, which is comparable to the angle of view of a standard lens.
Flash and ambient light measurement
The Sekonic L-308X measures both flash and ambient light from sources such as sunlight, LED lighting and other continuous light sources.
When measuring flash, shutter speeds from 1 second to 1/500 second can be selected, after which the light meter displays the correct aperture value. The flash can be connected using a PC sync cable and triggered with the meter’s measuring button. Wireless flash measurement is also possible by placing the meter in standby mode and triggering the flash manually or with a remote-control system such as Elinchrom Skyport.
When measuring ambient light, the L-308X supports shutter speeds from 60 seconds to 1/8000 second and displays aperture values across a very wide range.
Photo Mode
Photo Mode is designed for studio and location photography. Measurements for both flash and ambient light are clearly displayed on the screen. The meter supports both Shutter Priority and Aperture Priority modes, providing excellent control over exposure and depth of field.
HD Cine Mode
HD Cine Mode is designed for video production and provides access to a wide range of frame rates and shutter speeds. Support for ISO 850 makes it easier to work with the native sensitivity of several professional cinema cameras. Measurements are displayed with an accuracy of 0.1 stop.
Cine Mode
Cine Mode is designed for professional cinematography. Frame rate and shutter angle can be selected to provide the precise exposure control required for digital film production. Light levels can also be displayed in lux or foot-candles.
Accurate exposure readings
The Sekonic L-308X offers high measuring accuracy and excellent repeatability. When set to full-stop display, the measured value is shown with an accuracy of 0.1 stop. The screen can also be configured to display half or third stops to match the exposure settings of the camera.
ISO sensitivity can be adjusted from ISO 3 to ISO 8000 in third-stop increments. For film and video, several frame rates between 8 and 128 frames per second are available.
Compact and lightweight
The Sekonic L-308X Flashmate is one of the smallest light meters available for measuring both flash and ambient light. It fits easily into a shirt pocket or an outer compartment of a camera bag, making it convenient to carry wherever you go.
Despite its compact size, the L-308X is an advanced light meter used by professional photographers and filmmakers around the world. It is powered by a standard AA battery and weighs approximately 80 grams without the battery.
Technical specifications
| Model type | Digital light meter for flash and ambient light |
| Measuring methods | Incident and reflected light |
| Diffuser | Built-in sliding spherical diffuser (Lumisphere) |
| Flat diffuser | Lumidisc, optional accessory |
| Reflected-light measuring angle | Approximately 40° |
| Sensor type | Silicon photodiode |
| Operating modes | Photo, HD Cine and Cine |
Measuring ranges
| Ambient light | EV 0 to EV 19.9 at ISO 100 |
| Flash light | f/1.0 to f/90.9 at ISO 100 |
| Repeatability | ±0.1 EV or better |
| Incident-light calibration constant | Lumisphere: C = 340 Lumidisc: C = 250 |
| Reflected-light calibration constant | K = 12.5 |
Adjustable ranges
| ISO sensitivity | ISO 3–8000 in third-stop increments, plus ISO 850 |
| Shutter speeds for ambient light | 60 seconds to 1/8000 second in full, half or third stops |
| Shutter speeds for flash | 1 second to 1/500 second in full, half or third stops, plus 1/75, 1/80, 1/90 and 1/100 second |
| Shutter speeds in HD Cine Mode | 1/8 to 1/8000 second, plus 1/24, 1/25, 1/30, 1/48 and 1/50 second |
| Aperture range | f/0.5 to f/90.9 in full, half or third stops |
| Displayed EV range | EV −6.0 to EV 27.3 in 0.1 EV increments |
| Shutter angles | 45°, 90°, 180°, 270° and 360° |
| Frame rates | 8, 12, 16, 18, 24, 25, 30, 32, 64 and 128 fps at a 180° shutter angle |
Other specifications
| Out-of-range indication | Eu for underexposure or Eo for overexposure |
| Display | LCD screen with automatic backlight |
| Automatic power-off | Yes, approximately four minutes after the last measurement |
| Battery indicator | Yes, three-level icon |
| Power supply | 1 × AA 1.5 V battery (alkaline, manganese or lithium) |
| Operating temperature | 0 to 40 °C |
| Storage temperature | −20 to 60 °C |
| Dimensions | 110 × 63 × 21 mm |
| Weight | Approximately 80 g without battery |
Included
- Sekonic Flashmate L-308X light meter
- Protective case
- Strap
- Sync terminal cap

Sekonic manufactures professional light meters, colour meters and illuminance meters that help photographers and filmmakers measure and control light for accurate and consistent exposure.
Sekonic – Because it's all about controlling the light.