The Lumidisc for L-308 Series is used to measure the light falling on green-screen walls, paintings or flat art. It is also used to adjust lighting ratios with multiple light sources or when taking Lux and Footcandle measurements.
Measuring Contrast of Light
This method is useful for setting brightness levels (ratios) of key, line, hair, and eye lights for cinematography applications or evaluating studio lighting for Photo applications. It is also useful to check the evenness of illumination across a subject area or background such as a green screen.
Operation
- Slide the Lumisphere all the way to the right and attach the Lumidisc.
- Turn ON just the main light source. Point the Lumidisc toward the main light source from the subject position and take a measurement.
- Next turn ON just the secondary light source. Point the Lumidisc at the secondary light source and take a measurement.
- Determine the lighting ratio (contrast ratio) using the differrence of measured values of the main light source and the secondary light source.
| EV Difference of Measuring Value |
Contrast Ratio |
| 1 |
2 : 1 |
| 1.5 |
3 : 1 |
| 2 |
4 : 1 |
| 3 |
8 : 1 |
| 4 |
16 : 1 |
| 5 |
32 : 1
|
NOTE! To determine exposure after adjusting lights, turn ON both main light source and secondary light source, then take a measurement with the Lumisphere aimed in the direction of camera's lens axis.
Sekonic makes tools such as light meters, color meters and illuminometers to help photographers and cinematographers measure and control light for the perfect exposure.
Sekonic... Because it's all about controlling the light.