Light Meter Calibration Constant

Ideally you want to use a lux meter to measure the amount of light hitting a workstation or similiar.

Light meter calibration constant. The incident light calibration constant depends on the type of light receptor. The update speed is how often a new measurement is displayed. Is is almost impossible to measure the amount of light given off by 1 light in the conditions you describe. In your example the second reading is higher because the light meter is picking up light from the other lights in the area.

Calibrate a light meter. Set the same iso value e g. An incident meter should be pointed toward the camera a button is present on the side of the light meter. Graph shows the time depedence of the light.

Using k 12 5 the relationship between ev at iso 100 and luminance l is then. Two receptor types are common. A common choice is 12 5 canon nikon and sekonic. For rapidly changing light levels a lower time constant is best.

Light meter ap 881e light meter for plants illuminance meter lux meters with display 3999 range from 1 300 000lux unit lux fc max min back light data hold data storage by aoputtriver 32 99 32. With a flat receptor iso 2720 1974 recommends a range for of 240 to 400 with illuminance in lux. A flat receptor typically is used for measurement of lighting ratios for measurement of illuminance and occasionally for determining exposure for a flat subject. Properly the meter calibration constant as well as the iso speed should be stated but this seldom is done.

The time constant can be set to 0 5 seconds 1 second 2 seconds or 5 seconds. Flat cosine responding and hemispherical cardioid responding. Iso 100 in the external exposure meter and the camera and make sure that all correction values are at 0. Calibrate option if you have a calibrated light meter or known.

4 time constant options. Light meter calibration light meters are utilized in a variety of industries and applications including photography cinematography osha compliance security quality assurance photosensitive materials regulatory requirements process controls and clean room standards. Values for the reflected light calibration constant k vary slightly among manufacturers. Hold it down for few seconds while pointing it on the light.

Firstly you need to hold the meter in front of the subject. The app will average the data over the time constant weighting it with a linear fall off over the length of the time constant. The light meter then gathers the reflected or incident light levels as per the type used. To calibrate your meter we recommend the following method.

Switch the camera to manual mode and deactivate all functions that affect the exposure.