Up.Grade: Human Vision & Colour Pipelines
I thought I would be one of the few people who would be bothered to get up and into town for this technical 10:15am seminar. But to the surprise of both myself and the organisers, the auditorium of the MCK Orzeł was once again packed – though I’d learnt to arrive in plenty of time to grab a ticket.
Up.grade is an international colour grading training programme. Their seminar was divided into two distinct halves: the first was a fascinating explanation of how human beings perceive colour, by Professor Andrew Stockman; the second was a basic overview of colour pipelines.
Prof. Stockman’s presentation – similar to his TED video above – had a lot of interesting nuggets about the way we see. Here are a few:
- Our eyes record very little colour information compared with luminance info. You can blur the chrominance channel of an image considerably without seeing much difference; not so with the luminance channel.
- Light hitting a rod or cone (sensor cells in our retinae) straightens the twist in the carbon double bond of a molecule. It’s a binary (on/off) response and it’s the same response for any frequency of light. It’s just that red, green and blue cones have different probabilities of absorbing different frequencies.
- There are no blue cones in the centre of the fovea (the part of the retina responsible for detailed vision) because blue wavelengths would be out of focus due to the terrible chromatic aberration of our eyes’ lenses.
- Data from the rods and cones is compressed in the retina to fit the bandwidth which the optical nerve can handle.
- Metamers are colours that look the same but are created differently. For example, light with a wavelength of 575nm is perceived as yellow, but a mixture of 670nm (red) and 540nm (green) is also perceived as yellow, because the red and green cones are triggered in the same way in both scenarios. (Isn’t that weird? It’s like being unable to hear the difference between the note D and a combination of the notes C and E. It just goes to show how unreliable our senses really are.)
- Our perception of colour changes according to its surroundings and the apparent colour of the lighting – a phenomenon perfectly demonstrated by the infamous white-gold/blue-black dress.
All in all, very interesting and well worth getting out of bed for!
At the end of the seminar I caught up with fellow DP Laura Howie, and her friend Ben, over coffee and cake. Then I sauntered leisurely to the Opera Nova and navigated the labyrinthine route to the first-floor lecture theatre, where I registered for the imminent Arri seminar.
Arri Seminar: International Support Programme
After picking up my complementary Arri torch, which was inexplicably disguised as a pen, I bumped into Chris Bouchard. Neither of us held high hopes that the Support Programme would be relevant to us, but we thought it was worth getting the lowdown just in case.
The Arri International Support Programme (ISP) is a worldwide scheme to provide emerging filmmakers with sponsored camera/lighting/grip equipment, postproduction services, and in some cases co-production or sales deals as well. Mandy Rahn, the programme’s leader, explained that it supports young people (though there is no strict age limit) making their first, second or third feature in the $500,000-$5,000,000 budget range. They support both drama and documentary, but not short-form projects, which ruled out any hopes I might have had that it could be useful for Ren: The Girl with the Mark.
Having noted these keys details, Chris and I decided to duck out and head elsewhere. While Chris checked out some cameras on the Canon stand, I had a little chat with the reps from American Cinematographer about some possible coverage of The Little Mermaid. We then popped over to the MCK and caught part of a Canon seminar, including a screening of the short documentary Kolkata. Shortly we were treading the familiar path back to the Opera Nova and the first-floor lecture theatre for a Kodak-sponsored session with Ed Lachman, ASC, only to find it had been cancelled for reasons unknown.
Red Seminar: High resolution Image Processing Pipeline
Next on our radar was a Red panel. I wasn’t entirely sure if I could handle another high resolution seminar, but I suggested we return once more to the MCK anyway and relax in the bar with one eye on the live video feed. Unfortunately we got there to find that the monitors had disappeared, so we had to go into the auditorium, where it was standing room only.
Light Iron colourist Ian Vertovec was talking about his experience grading the Netflix series GLOW, a highly enjoyable comedy-drama set behind the scenes of an eighties female wrestling show. Netflix wanted the series delivered in high dynamic range (HDR) and wide colour gamut (WCG), of a spec so high that no screens are yet capable of displaying it. In fact Vertovec graded in P3 (the colour space used for cinema projection) which was then mapped to Netflix’s higher specs for delivery. The Rec.709 (standard gamut) version was automatically created from the P3 grade by Dolby Vision software which analysed the episodes frame by frame. Netflix streams a 4,000 NIT signal to all viewers, which is then down-converted live (using XML data also generated by the Dolby Vision software) to 100, 650 or 1,000 NITs depending on their display. In theory this should provide a consistent image across all screens.
Vertovec demonstrated his image pipeline for GLOW: multi-layer base grade, halation pass, custom film LUT, blur/sharp pass, grain pass. The aim was to get the look of telecined film. The halation pass involved making a copy of the image, keying out all but the highlights, blurring those highlights and layering them back on top of the original footage. I used to do a similar thing to soften Mini-DV footage back in the day!
An interesting point was made about practicals in HDR. If you have an actor in front of or close to a practical lamp in frame, it’s a delicate balancing act to get them bright enough to look real, yet not so bright that it hurts your eyes to look at the actor with a dazzling lamp next to them. When practicals are further away from your cast they can be brighter because your eye will naturally track around them as in real life.
Next up was Dan Duran from Red, who explained a new LUT that is being rolled out across their cameras. Most of this went in one ear and out the other!
Afterwards, Chris and I returned to Kung Fusion for another delicious dinner. The final event of the day which I wanted to catch was Breaking Bad‘s pilot episode, screening at Bydgoszcz’s Vue multiplex as part of the festival’s John Toll retrospective. Having binged the entire series relatively recently, I loved seeing the very first episode again – especially on the big screen – with the fore-knowledge of where the characters would end up.
Later Chris introduced me to DP Sebastian Cort, and the three of us decided to try our luck at getting into the Panavision party. We snuck around the back of the venue and into one of the peripheral buildings, only to be immediately collared by a bouncer and sent packing!
This ignoble failure marked the end of my Camerimage experience, more or less. After another drink or two at Cheat we called it a night, and I was on an early flight back to Stansted the next morning. I met some interesting people and learnt a lot from the seminars. There were some complaints that the festival was over-subscribed, and indeed – as I have described – you had to be quick off the mark to get into certain events, but that was pretty much what I had been expecting. I certainly won’t put be off attending again in the future.
To learn more about two of the key issues raised at this year’s Camerimage, check out my Red Shark articles: