Rejection values

[Walcho]

Hello PI Expert !

I use PI for several years and now I would like to understand more precisely what is happening behind the sliders.
For example, I make my pictures with a DSLR Canon 1000D :
When I do the pre-processing, I move the sliders so that the total rejection will be, if possible:
0 0.100% (0.050% + 0.050%)
Why ? Because I was told that it was a good value and actually it works quite well.
But 0.200% also works pretty well.
So why not 1,000% or 0,010%? I do not know why.
I'll be really interested to understand what it means regarding to the picture and according to what ? Is there a formula to determine the best value based on its sensor?
I have to tell that I didn't do mathematical study, but if it's well explained I will certainly be able to understand.
Or, if there is a link that explains it quite simply?
(I understand French, English and German)

Thank you in advance for your support.

[Geoff]

Have a look here for a good exposition. It uses an earlier version of PixInsight, but that shouldn't be a problem.
http://www.astrosurf.com/jordigallego/articles.html
Open the article entitled "Image Integration techniques....."

[Walcho]

Thank you for this interesting link.
I quickly looked at it and there is a lot of information to better understand the subject.
On the other hand, I am not sure that there is an answer to my question inside, but according to what I could read, there is not necessarily a formula ready-made and an answer by default.
I in any case will read again the document more carefully  and I will start to learn Spanish to read the others!