Neutral Density Filter
ND filter enables light measurement from 50,000 to 200,000 Lux
Compatible with the Essence Pro, Standard Pro and Flagship Pro
Provided with ND filter case for easy attachment and removal
Can be sold separately or as a Lighting Passport kit
Measured illuminance correction factor = 4.17X
Measured colour correlated temperature correction factor = 0.93X
Asensetek Canada proposed to replace the Lighting Passport High Lux model which is capable of measuring illuminances up to 200,000 lux with a Standard Pro model and a neutral density filter coupled to the aperture. The High Lux model has been discontinued and the Standard Pro model is only capable of measuring up to 50,000 lux. Customers who would like to measure the illuminances of their high intensity fixtures and with the discontinuation of the High Lux model, have no means to do it.
The idea is to use an OD 0.6 neutral density filter that works in the visible range and has a transmission of nearly 20% to be placed on the diffuser of the Standard Pro to measure high intensity light fixtures. What needs to be calculated is the exact multiplication factor to be used once the Standard Pro measures the illuminance with the neutral density filter to give the actual illuminance. In addition, it has to be investigated if the presence of the ND filter alters the other photometric and colorimetric parameters such as colour temperature, CRI index and TM30’s Rf and Rg values.