When it comes to calculating projection brightness or resolution, people get confused easily. Let’s cut the bullshit and get straight into what matters.
There’s one single number that matters the most in projection-mapping screen quality and if you have this single number right, everything else will be correct too as a natural consequence. This single one most important technical number in outdoor projection-mapping is called The Illuminance.
It is so important that it even has its Wikipedia page: https://en.wikipedia.org/wiki/Illuminance
Illuminance
The by far most important parameter that matters when it comes to evaluating the visual quality of the projection screen is https://en.wikipedia.org/wiki/Lux (not to be confused with projector brightness or other technical value). Illuminance is a measure of how much luminous flux is spread over a given area. In digital projection mapping, we calculate illuminance from two values:
Value 1:
Effective Brightness of the projection system, EB, ASNI lm
Value 2:
Illuminated Area, IA, m2
Math
Illuminance E = EB / IA lx (lux) or lm/sqm (lumens per square meter)
Let’s try this on a simple example:
Our projection system consists of a single LUMITRIX LAZR device. The Effective Brightness of this projection system is EB = 6 000 ANSI lm.
Our Illuminated Area is 60 square meters, IA = 60 m2
So the resulting illuminance E of the system is
E = EB / IA
E = 6 000 / 60 E = 100 lx
100 lx is a very reasonable illuminance, which is in my opinion enough in most applications and allows for a reasonable project budget with a fantastic impact. Anyways, the point is: If there’s a single number that evaluates, how bright or dull the projection screen is, it’s The Illuminance.
In case you’d like to skip the math and see the calculation results for your use-case, why not trying the Lumitrix Configurator