Caluclate lux value from LDR I am using an LDR (Iduino SE012) to measure light. It returns a 10-bit value of the incoming voltage and I don't know how to convert this into lux, lumen candela or any other light-intensity unit. I was googling for datasheets but nothing useful came up. So is there any way how I can extrapolate a light intensity from the voltage? 

I mean one idea that I would have is to measure some things where I know the lux output, but since I don't have such things or a luxmeter I'm pretty stuck. It also returns 1024 pretty quick if you hold it into the sun (Altough the sun is very strong today and it has 36°C). Is there maybe a "minimal value" at wich it returns the full voltage? From that point I could calculate it for all the other values.

Here are some datasheets I found: 


https://www.manualshelf.com/manual/iduino/se012/datasheet-english.html
https://wakamatsu.co.jp/waka/SE012.pdf
You can't.

The LDR has a spectral sensitivity which is very different from the
human eye's. The definition of the lux, or any photometric unit for
that matter, pretty much requires that your sensor is filtered in such
a way as to have the human eye's spectral sensitivity.