Exporting using Alpha Channels 'Straight' and 'Premultiplied'

Anyone know of a work around or solution when exporting using alpha channels. Usually exporting with the ProRes444+ or 'Animation with Millions of Colours+ At first seems to do the job, but doing it this way always leaves a very slight black edge. The main reason for this is that it seems to be using by default a “premultiplied alpha”. Ideally for a sharper/cleaner alpha I would want this to be “straight alpha”.

I can get around this currently by running this through After effects then re-rendering but this seems daft. I have messed with the write modules and nothing straight forward seems to fix the problem. Exporting as PNG’s and so on in my opinion is also long winded and over kill and results vary. Especially when all I need as a setting in the movie export somewhere to change the alpha type…

The difference between straight and premultiplied is huge when you compare closely, with straight alpha giving a much sharper render.

Any suggestions anyone or maybe I’m missing a setting somewhere…

Thanks, Jason.


Storyboard Pro and Harmony 11 user.