Donāt forget to join us this Thursday at NOON ET for @RufusBlackwellās Autodesk Vision Series VFX breakdown titled: Camila Cabello & the Toughest Green Screen Shot Iāve Ever Undertaken.
Loved this presentation and Autodesk must host more of these in terms of Flame. As David said there was a wealth of parts or knowledge-nodes that all add up to a whole, as complex as the schematic Rufus built.
One thing struck me, and perhaps tells of my lack of knowledge. When discussing the matte motion blurring with using the motion analysis+motion blur, Rufus mentioned 90 degree shutter at acquisition and not 180 degree. Is this an camera+vfx technique that I am unaware of and that it is better to use 90 degrees or less and for better compositing and separation? If so, this reminds me of a āfixā that someone discussed on a video I was watching in terms of the new gyro on the Blackmagic cameras and using a 60-90 degree shutter speed to compensate for the rolling shutter with the new gyro-stabilisation for a better stabilisation. They were talking about it not introducing as many motion artefacts when stabilising and so then introducing motion blur in Resolve to get to the 180 degree look.
If I am understanding it with composites, this makes sense as you can separate the elements easier in the shot and then introduce the 180 degree in post. Again, I may be showing a lack of knowledge, but this sounds really interesting, and a bit like degrain and regrain to bury the bodies? Iāll give this a try on my Blackmagic 6k Pro.
Again, great walkthrough and cannot wait for it to be uploaded to pick it apart a little.
Cheers
Tony
PS, interesting also in terms of the colour grading methodology in bypassing the effects tab. You wouldnāt think of using Fusion in Resolve instead of the colour tab, but the complexity of the work that Rufus was undertaking made sense.
Yes, a shorter shutter does reduce motion blur and makes certain tasks easier. In my experience, ya better have a really good reason to ask the Director of Photography to change her shutter, as it really does change the look and feel. And, when you mess with the look and feel, clients get used to it and then one day you add all the motion blur back in (which, works, but requires some painting and finessing and isnāt a one click dealio) and the clients complain that now it looks all blurry and they cant see anything and you ship a skinny shutter and the DP sees it and she calls you and complains that you ruined her film.
In my market the labor costs for Flame are so high that weād outsource that keying in a heartbeat so for me Iād rather pay someone else a few extra bucks a frame to deal with motion blur it so I can improve (I mean, not ruin!) my relationship with the DP.
Completely agree. Unless someone is asking how do I make this look like saving private Ryan or gladiator, Iām not telling anyone what to do with the shutter angle just so I can get a key. Almost every plate youāre ever going to key is going to be a 180 shutter. If itās not, someone made that choice for reasons that they felt were necessary, and those reasons probably didnāt have much to do with the vfx.
This was shot with a drone, with the Red cam on a gimbal, and while the gimbals are good, the stabilisation is not pixel perfect especially at 6K. So if it had been shot with 180 degree shutter you would definitely see the baked in motion blur looking weird once it was stabilised. 90 degree shutter is often a good compromise. I can always add motion blur but canāt really remove it much.
The post process for this was quite convoluted, I took the 6K RAW, denoised it with Neat video, exported and used Warp Stabiliser to take the jitter out, then upscaled it to 12k with video enhance AI, that further sharpens the image, undoing any softening from the stabilisation process and has quite an effect on the overall look, then back in to Flame, back down to 6K, and thatās my source file for the project. Really cool technique to get clean, sharp looking beautiful source images. Then bringing the CG and the live action together and tweaking to get it looking like one cohesive whole, including tweaking the motion blur for both.
Personally there are many instances where I will have a discussion with the DoP about which shutter speed, resolution, frame rate etc. we should be shooting the get the elements right for post. So for example if theyāre planning on doing some time remapping in post, then we might go for 50 or 100fps to give us the intra-frame information for a time remap, even if we have to lose some resolution to get it. Again in that instance I would ask for a fast shutter speed because you will need to be creating the correct motion blur in the time remapping process. Often each result frame will span across multiple source frames, but with that info the time remap tool (TimeWarp, sigh) will have the info it needs to create correct 180 degree motion blur, even across a ramped time remap.
Also if youāre planning on slowing it down with the amazing ML timewarp tool then you would want the source images to be as sharp as possible. Baked in motion blur in slowed down images doesnāt look great.
Probably quite soon we will have a AI tool to effectively remove motion blur, canāt be far away I reckon. I saw it demoād on stills a while ago, but I havenāt seen any tools available to us yet.