Motion Blur Edges for Green Screen Comps

A cool technique for getting natural motion blur edges on green screen comps. Actually not just green screen, anything where you need to re-add motion blur to soften off a comp. For example if you have roto’d a finger over a screen comp this is useful. I pull this setup out of my user bin all the time.

This was featured in the Siggraph presentation I just did, and a few people were interested in it, so here it is with the setup:

The batch setup:

The same as an archive

Let me know if it’s useful for you




Thanks so much for posting this. Great presentation too!

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Beautiful work and thanks for this supplemental bite out from the whole.

I misremembered the part about the motion blur in the original footage so I wonder if 90 degree shutter speed at the acquisition stage would help with keying? As with dual ISO I wonder if sensor manufacturers might introduce dual-shutter, and you could then eat have more freedom in mixing and matching and cutting if you had access to them both?



Thanks so much for posting this. When you mention you’ve done some Wash on the motion blurred edges at 1:50, where did that Wash come from? Did you just sample the color of her dress and Paint it a frame at a time? Thanks!


Thanks much for sharing the setup. Your presentation was great today. A lot was packed into that hour. Some really cool techniques.


very cool technique, thanks Rufus…can’t wait til the whole presentation is available to view.


Yup thats basically exactly it. I think sampling a brighter, highish saturation area worked best on this one. Then use the wash option in the paint mode menu.It’s something we used to do more often, and somewhat considered a dirty fix, but in this case with transparent red on green, to two being opposing colours, it did help.


Thanks @RufusBlackwell for the tips. I love a bit of wash. If it helps anybody, another way to get this to wash without paint is to use @miles y sample and use the chroma (UV) of that with Y of front in a matted area.

Again for posterity only: for transparent edges I always like to recall this tutorial which can get some nice edges too.

Credit to Dumbledorf for this.


I love this technique :point_up:


stumbled upon this today and had a play with it but it does not seem to work with some blue screen material that i have. also i’m working in ACES so maybe the math is wrong as Dumbledorf’s footage looks like rec. Anyone get this to work? @johnt


I have used this in the past and i think I have done it correctly.

flame 2020.3.1 - Dropbox - - Simplify your life

Sorry for the delay @TimC

Convert to aces cct ie log for any stuff like this or grading using input transform then invert to get back. I’m always jumping in and out of log.