Hello !
I’m trying to render a cigar with a smoke simulation on transparency alpha png.
In the viewport and the render, the smoke looks perfect,
but when i’m saving the image for composite, the smoke opacity gets altered as you can see in illustrator (png on black background).
I’m using basic render and saving settings (png,16 cdepth,with and without comp) but it is still the same.
It’s very frustrating because the render looks perfect in blender.
Thanks a lot 
Are you sure you selected RGBA in the Output Properties → Output → Color (or accidently selected just RGB in the toogle region of the Blender File Viewe)? Because if just RGB then blender shows the transparency but don’t export it (just checked).
I just verified and it is RGBA… I don’t understand from where is it from
Okay that’s weird 
… and the app don’t just show alpha as black? i mean further mixing just show black…? (sometimes there is that problem with
Alpha storage can be associated (premultiplied) or “unassociated”…
but shouldn’t here 
I’m sorry i didn’t really understand your question, the smoke gets altered on every app i use to open it.
(sorry for my english im french)
I just found that the alpha canal in the composite render is different to
the color canal. Maybe it can be helpfull to find the problem.
Why is it making these line?
I also found just yet that the glare maybe is doing something wrong with the alpha channel (the premultiplied problem i meantion earlier… maybe this was it with using compositro and low valued alphas). Maybe just turn composite off for a test?
Edit: ahh maybe have a look at this StackExchange: Blender does not set the alpha channel correctly
Then it this was the thing with to small values in combination… wait i have to updat my notes 
