VRT Sandbox facilitates 4K production test
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Loslopend Wild en Gevogelte (LLW) is a VRT TV Comedy show.
The show consists of short humoristic clips and airs from November 2105 to January 2016, once a week in a season of 10 episodes.
Together with the VRT production team of LLW we've produced 5 sketches of this season's LLW in 4K resolution.
The objective of this project was to find out what it means for VRT to run through the whole end-to-end production process that is needed to deliver 4K content.
As 4K consumer devices are becoming more mainstream, 4K production is an essential process to control. And what better way to learn than by doing?
First step is of course the recording of the content itself.
This starts with the camera and the recording medium.
In this case we've recorded on the Arri Amira (a very popular big-sensor camera at VRT), on compact flash cards. The codec we used was the Apple ProRes 4.2.2 HQ codec which provides a visually losless codec, still at a reasonable bitrate.
At the same time we recorded the HD version of the same takes by connecting the HDSDI output of the camera to a time synched SoundDevices pix machine. Like this we would end up with a bunch of takes that had each time a 4K version on the camera memory cards as well as an HD version on the sounddevices pix. Both versions were using LogC.
What we found out immediately is that when you're shooting 4K, the time to copy and process these bigger files becomes much longer. Something we didn't really anticipate and made our cameraman miss lunch!
So if you go in the field and want to do some media management on 4K material, make sure to have enough cards and usb3.0 harddrives (and cables!) and maybe an additional laptop with USB3.0 ports to do copy actions in parallel.
Next step was to import and edit the material in our AVID-MXFServer environment. Needless to say that you need more storage to store 4K material over HD material, an important consideration if we would start to do complete productions productions in 4K.
As LLW is a real VRT production in HD, we decided to try out the following: we edit everything in HD on AVID, finalize the audiomix and the colour-grading following the normal LLW HD workflow. At the end when the clip is ready in HD, we will relink the 4K rushes in the Nukoda colour-grader, which should be able to deal with 4K files since an upgrade we did earlier this year 2015.
And so we did, and so it went fine!
The only in-between step we had to take was to import the Avid edl into Adobe Premiere and do the relinking over there, simply because it is just less hassle to do it in Premiere then in AVID. Also as AVID renames every clip on import, our initial plan of having the same clip with the same name and duration and "fooling" the colorgrader in the end by replacing the rushes from HD to 4K failed pretty much.
As we will start editing on Adobe Premiere at VRT in the near future, this in-between step will become unnecessary.
We imported this 4K adobe edl in the Nukoda colourgrader with great ease.
Last step was to do a colourgrading session on the 4K material. Previous tests had shown us that colourgrading is all about dynamic range and correct colours. As we don't own a 4K grade A reference monitor, we did the grading on our grade A HD monitor, rather than asking around for a 4K grade A on loan.
As VRT sandbox is all about sharing our learnings, we've uploaded our end-result on Youtube, one of the more evident places to store and publish your 4K content. In Belgium the Telco's are not really offering any 4K outlets so far, other than OTT.
You can watch the clips by clicking on the thumbnails. Please feel free to share your opinion on the quality of the end-result!
Thank you for all the people involved in this test: Riet De Prins, Tom Bonroy and the LLW production team, Geert Groeseneken, Pedro Chitiaens and the VRT T&O Postproduction team and VRT Sandbox for making this happen!
Karel De Bondt