Composition issue

#1

I simply want my composited render to look exactly like my beauty render but when overlaying the 2 final pictures on top of each other in After Effects, there is always a slight difference. As for my composited layers, it’s super simple consisting of one scene render of my foreground 3D objects with mia_sky “use background” checked ON and no texture plugged so the backgrounds is pure black and another render of my mia_sky background with all the rest hidden. I have “pre-multiply” checked on in the render globals and when importing to After Effects I check “premultiplied with black” in the import footage settings. I don’t understand why I don’t get the exact same result as my beauty render. What am I doing wrong?

[http://sor.typepad.com/.a/6a00d8350600cb53ef01a511ca0b9f970c-pi](http://sor.typepad.com/.a/6a00d8350600cb53ef01a511ca0b9f970c-pi)
 
 [http://www.filefactory.com/file/338olg75her1/4_composotion_issue.7z](http://www.filefactory.com/file/338olg75her1/4_composotion_issue.7z)
#2

The same issue happens with the .EXR format, Here is a link to the project so if you check the EXR renders in the image folder, and composite them you should see the difference. I also attache an After Effects projects in the same folder where comp1 shows the difference between the 2 results (comp2 is the background and foreground combined together):

http://www.filefactory.com/file/667pwgvy8gjb/beauty_vs_composition_issue.rar

#3

I think you got amazingly close, only the anti-aliased edges are different.
Try turning off the pre-mult option. This will get even closer.
When you try more passes like indirect and reflection or refraction this will be more challenging.

#4

pre-mult should be turned ON since this how it was rendered in Maya.
I dont see why I am not getting the same result.