Re: [Gimp-user] Layer addition - bug, feature, or user misunderstanding?

[Elle Stone <ellestone ninedegreesbelow com>]

On 10/13/2015 10:55 AM, Elle Stone wrote:
> So does this seem like a bug in the Addition blend mode? Or is there
> something I'm not still not understanding about how Addition layer blend
> mode is supposed to work?

Hmm, Krita produces the results I expected, that is, the three layers 
add up to R=G=B=1.0f.

So either GIMP intentionally uses a different algorithm for addition 
blend mode. Or else there's a bug in the code, most likely the same bug 
reported here: https://bugzilla.gnome.org/show_bug.cgi?id=744265. I'll 
add a comment to that bug report.