DYNAMIC PREMULT a look at a technique which allows you to comp quicker and not worry about maintaining and managing your premultiplication if you have any comments or questions please leave one below to download the source footage CLICK HERE Posted In: home, tutorials
i like your tutorials and your work a lot, but i think that this tutorial is misleading.
The problem starts when your outputting you matte with a comped Front on black, if you would leave the front as it is for the later comp there would be no edges.
The Pixelspread you late show is actually nearly like using your Front (not the Comped Front on Black) but it changes the pixel information in your Front image. You'll notice that if you comp your Pixelspread Result back on your original Front.
The divide operation (unpremultip your Front) you mentioned is the way to go, for you premultiplied Front Image, thus you don't change your Front and achieve clean edges.
I do agree with you that pixelspread does change your pixel information in your front image, and usually this isnt my first approach to keys, however when i am in the situation where i have to pass keys off to AE or elsewhere i've had decent results with this technique, albeit not mathematically correct since you are introducing stuff into the plate that wasn't there. Its not meant to be a replacement to the right way of doing things through divide then multiply technique, merely something i came across in a recent job when i had to hand off graded+keyed footage to be later comped in AE where i didn't have acces to the bg plate at all,
sorry ur not into this one, i've got more coming :)
that was no offense, don't worry. I really appreciate what you are doing in your tutorial section. It is cool to get new input or share workflows.
The real problem is flame/smokes way of handling premultiplied footage, i really hope they will introduce the clean way like in nuke in future releases.
I'm looking forward to see more tutorials from you :)
i hope flame/smokes way of handling premultiplied footage gets adressed too, its too many steps and i agree should be alot more transparent,ReplyDelete
Am really enjoying your videos, even being a 17 year Flame vet. The question I have about this particular one, is that it seems possibly redundant if you're already running a Pix Spread expansion on the fill (which I use all the time). If you're expanding the edges, whether you're using it downstream or feeding it to AE, etc., then the pixels that are affected by interpolate aren't relevant, right?
Had a job where I tested this out today and when using expand, interpolate made no appreciable difference.
Please do prove me wrong though!
Thanks for all your sharing.