Melanopic illuminance

(aka Circadian lighting, melanopic lighting, healthcare lighting, etc)
The BTS256-E and BTS256-EF have recently been updated to include:
Non-visual response measurands
In addition to conventional rods and cones, the retina has melanopsin-containing photosensitive ganglion cells. Vision scientists have demonstrated unequivocally that melanopic light reception affects brightness perception and that the conventional photopic measurements require a correction to maintain a proper correlation with perceived brightness. In cooperation with the researchers who originallydetermined this correlation factor, Gigahertz-Optik now includes this Melanopic/Photopic and Brightness Perception function in the BTS256-E series meters.

The BTS256-E displays:

• E (Melanopic / Photopic) display title
• Ep – This is Photopic Illuminance (lx)
• Em / Ep – This is Melanopic Irradiance (mW/m2) / Photopic Illuminance (lx) = mW/lm
• Em’ / Ep – This is Melanopic Illuminance (lx) / Photopic Illuminance (lx) = unit-less ratio
• B0.32 – This is Brightness Perception (lx) – other user defined constants may be input through menu setting

Find more inf about the BTS device Find more info here!