davidbush          

8k 12k - some considerations for practical use

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         Top right Peter Swinson in 2007 and bottom right in Chicago when working for Bell & Howell, holding their Technical Oscar.

                                                                                                                                       Below, Blackmagicdesign Ursa Mini Pro.



RAW Files are another clever idea that has also been developed by camera manufacturers to get the best possible image quality out of digital cameras while using the least amount of data.


Images from cameras that can shoot in raw are perfect for colour grading with Da Vinci Resolve as they contain all of the original highlight, lowlight, and mid-tone information, they enable the full image latitude and HDR, and yet the files are made of reasonable amounts of data.


Post production can be made simpler and more efficient by not converting files into other formats, and, indeed Resolve is an excellent example with its capability of being able to work directly in native raw files. Why transcode to any other format? Doing so would be a waste of time, a waste of space and also a waste of money, whilst it would also potentially degrade the image quality.


4. Film Restoration in 8k with Pro Res XQ compression


Carefully controlled light compression schemes can also be applied to film originated materials as well as digital cameras, and which give the resulting 8k mastered and restored films an extremely impressive look. The standard 4k 16 bit DPX files that have been up to recently the usual mastering format, require in playback a data rate of some 405 MBytes/sec, whereas the same film scanned in 8k with Pro Res Raw XQ is a higher (but manageable) amount of data, with an incredible increase in picture quality. In numbers, the maximum quality Pro Res XQ file of an 8k film at 24 fps. is 848 MBytes/sec. On the other hand, an uncompressed 8k 16 bit dpx file would be a whopping 8018 MBytes/sec, or nearly 10 times as much data.


The point is that the 8k pro res offers visually lossless compression, or, in other words a result indistinguishable from the uncompressed version.


Those that have not yet seen the kind of result possible with 8k scanning of films state with conviction that 4k is “enough” for 35mm films. The Mobile Digital Lab pushes the benchmark from “enough” to "excellent", and for good reasons; it offers an analog style purity and subtlety with a pristine quality, in what could also be defined as a possibly better than projected film experience.


The practise of oversampling, or using higher resolutions to shoot and scan offers, in our opinion, better image quality for the finished product, and now that the technology has become eminently enabling for 8k and beyond, there’s no excuse not to use it!! It will look better!! And it won’t cost more!! Indeed, with Mobile Digital Lab it will cost less!! And I haven't even mentioned the fact that shooting in 8k or 12k offers future proofing for the production. On that note, it is also worth noting that using the aforementioned techniques renders remote working eminently more efficient as the reduced data rates mean faster transfer times over the internet.


See my experiences in digital film restoration.



5. Lossless - A type of codec for which putting an image through encoding followed by decoding results in an image that is mathematically guaranteed to have exactly the same pixel values as the original.


6. Visually lossless - A type of codec for which putting an image through encoding followed by decoding results in an image that is not mathematically lossless, but is visually indistinguishable from the original when viewed alongside the original on identical displays.



Personally I'd like to state that there’s nothing wrong with a little compression when working with 8k or 12k imagery.


Let me explain: early one afternoon some 20 years ago a jovial young boffin called Peter Swinson of Rank Cintel demonstrated how, by scanning images in ever higher resolution, it was possible to use ever higher levels of compression, generating smaller files. It seemed a miracle: using Peter's techniques we got smaller files, less data and yet higher quality pictures.


Certainly, his work stimulated many of us to imagine that compression would become rather important from then on, and, indeed, it did.


Over the years I’ve also come to the practical conclusion that small amounts of compression can be used effectively for mastering, editing, grading etc. in a pro-active way to reduce costs, while also reducing storage requirements and expense. What I mean by that is that uncompressed formats are usually several orders of magnitude heavier in terms of data than such lightly compressed versions and, as the lossless compression is indistinguishable from the uncompressed master, can be somewhat inefficient if used for post, as these heavy files will inevitably cause the need for much more data storage and more computing power.

HDR

HDR

1. The theory of compression with high resolution images.

2. The Blackmagic Ursa Pro 12k and the Red Monstro 8k with 5:1 compression

3. And on comes RAW

In the case of the Blackmagic 12k, for example, the uncompressed image of 12,288 x 6480 pixels would require 7.220 Mbytes/sec to playback at 60 fps, whereas if we use the lightest compression of 5:1 this requires a much more modest 1.500 Mbytes/sec. In the case of the Red Monstro the camera's output is 5:! compression, as there is no uncompressed output. Shooting 8k at 60 fps. this gives a data rate of 300 Mbytes/sec. The excellent results and quality of the images tell the story by themselves.


The point is, since we can’t see any difference between the two, surely needing only one fifth of storage requirements and lighter processing in post are advantages. And, indeed they are.


To the sceptical, and to prove that there really is no visible difference, I have sometimes offered in my work to put two images - one compressed and one not - in comparison side by side. I have yet to find pairs of eyes capable of getting right consistently which was compressed at 5:1 and which no. Even with big screen projection, and even with A-list directors, and however close I've put them to the screen. Lossless really does mean lossless (see below).










Although HDR (high dynamic range) and HFR (high frame rate) are far more valuable than resolution to the consumer’s eye, there are other benefits with an 8K - 12K production which an increasing number of projects are taking advantage of. These are better results for keying, composites, colour grading, tracking, stabilisation and indeed practically all of the operations necessary for visual effects, not to mention extensive possibilities of re-framing.


Yes, 8k and 12k represent a new benchmark that requires powerful computers configured appropriately for high resolution formats to edit and grade it, but that’s exactly what cutting-edge post production facilities should now be able to offer to their clients.


Grant Petty, CEO of Blackmagic Design adds;


"With the new Apple Mac Pro we see full‐quality 8K and 12K performance in real-time with color correction and effects, something we could never dream of doing before. DaVinci Resolve running on the new Mac Pro is easily the fastest way to edit, grade, and finish movies and TV shows.”


Based on Mike Connor's and my collective professional experiences and recent quantum leaps in the technology our Mobile Digital Lab functions both as a complete DIT workstation and as a creative editorial hub with on line editing, colour grading, sound and visual effects in the final quality resolution. It is the equivalent of a fully fledged post production facility that can be set up in less than an hour near shooting or even directly inside a film studio. It offers a simple, practical, cost effective and fast workflow for finishing high resolution 2k, 4k, 5k, 6k, 7k, 8k and 12k films and television series, shaving many weeks and months off the usual time to final delivery with the current standard methods, while also helping save overall costs along the way.