KeyShot Forum

Technical discussions => Lighting => Topic started by: andy.engelkemier on February 23, 2021, 08:16:59 AM

Title: Is lux in keyshot correct?
Post by: andy.engelkemier on February 23, 2021, 08:16:59 AM
I was looking at a definition of Lux provided by keyshot on their blog, and I'm a bit confused.

Lux
Lux, or Lumens per square meter, is a measure of light intensity that takes into account surface area
A one-square meter surface emitting 1,000 Lux will appear brighter than a two-square meter surface emitting the same 1,000 Lux. The overall brightness is decreased as the light is spread across a larger surface.

Well, that doesn't make sense, does it?
By definition, saying lumens per square meter would suggest that if you have a material describing 1000lux, and you apply it to a 1 square meter plane it should produce 1000 lumens. If you apply the same material to a 2 square meter plane, it should produce 2000 lumens NOT 1000 lumens, as the second bullet point suggests.
They should both appear exactly the same brightness, but the larger the object, the more overall light it produces.

Am I not understanding this correctly?
Title: Re: Is lux in keyshot correct?
Post by: Higuchi on February 23, 2021, 05:32:24 PM
This might me your reference. This is the same what I posted on other thread at the same time where I communicate with you.
https://manual.keyshot.com/manual/materials/material-types/light-sources/area-light/
Title: Re: Is lux in keyshot correct?
Post by: andy.engelkemier on February 23, 2021, 05:36:15 PM
Yeah, I see that. I saw a blog post Will G did, but he must have mixed up the definitions in it and never went back and fixed it.
It's funny that blog posts come up in search before the manual. But so it goes.