Transparent background in render is coming out black?

I am running a render for an animation that is set up in the compositor below :

The image in the background has alpha transparency (due to film - transparent being enabled in the render settings) , and this is exactly what I want. However , the image file that is saved has a black background - which is what I don't want....

Just to clarify , the two render layers are the logo in the top layer  and the bulb on the bottom layer in three compositor. Surely the alpha over is just applying the bulb on top of the logo , s where is the black background magically appearing from? 

Why is this happening and how can I fix it? 

Thanks in advance for any help :) 


  • spikeyxxx replied

    Hi Matthew, could it be that it is your image viewer that adds a background color like mine does:

    As you can see opening it in Blender, it shows the blocked Alpha BG that you are used to, but the same Image in Gwenview shows a dark grey, but the Alpha is still there. I can change the BG color if I want:


  • tanya (tanya53) replied

    if spikey's answer didn't work, this is what I had to do using one alpha over.  I had to connect the alpha from the image Fac of the alpha over or it didn't work for me.


  • Matthew Fricker(frikkr) replied

    Thanks spikeyxxx and ttanya53 , I'll have a play around and see what works :)  

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