Photometrics metrics on lights? 1M vs 2M?

[analogs]

Looking at the light brightness specs of COB lights, some measure it at 1m and others at 2 meters.

Do you just double it when reading 2 meter readings, to get the 1 meter equivalent or is there a formula to it?

Thank you.

 

[ahalpert]

Light intensity diminishes exponentially with distance according to the inverse square law. Intensity = E/(distance^2)

So at double the distance it will be a quarter of the brightness.

https://images.app.goo.gl/AScW3aBL4nmW5U3D7

 

[analogs]

Light intensity diminishes exponentially with distance according to the inverse square law. Intensity = E/(distance^2)

So at double the distance it will be a quarter of the brightness.

https://images.app.goo.gl/AScW3aBL4nmW5U3D7

Thank you ahalpert!