If there’s something we’ve discovered about our readers over time, it’s that you just love content material about all things color related. So we received impressed: what if we began a sequence of stay demonstrations protecting all the most important colour grading functions which have integrations with Frame.io?
Last month we launched the primary in our sequence of Frame.io Fundamentals stay occasions, starting with Lumetri, Premiere Pro’s highly effective colour grading instrument. We have been thrilled to see so a lot of you attend, and excited by your engagement with us and the good questions you requested. You can watch the total session under, however we thought that for these of you who study higher by studying, we’d present a abstract of the session that highlights the important thing factors we lined.
And by we, I imply our host Shawn McDaniel and me, the in-house colorist at Frame.io. I’ve been privileged to work with a few of the world’s greatest colour scientists on some wonderful initiatives all through my profession (like remastering a few of the Marvel titles to HDR), and I’ve a ardour for each the artistic and technical aspect of the ending course of.
Fundamentals of additive colour concept
If you’d like to look at as you learn, we start this part of the dialogue at roughly ten minutes into the video.
Additive colour concept relies on how the human eye perceives the seen spectrum of sunshine. The eye has three receptor cones which can be, respectively, delicate to wavelengths of seen mild within the crimson, inexperienced, and blue areas—the three main colours. It’s known as additive colour concept as a result of should you add various quantities of the first colours, you possibly can obtain all perceivable colours.
Mixing them collectively at full depth yields white mild; eradicating them equally yields black (the absence of colour); and mixing the first colours in varied mixtures yields the secondary colours—yellow, magenta, and cyan. The distinction between black and white is called your luminance vary (also called distinction ratio or dynamic vary).
[At 12:10] If you have a look at these acquainted colour wheels, you possibly can see the crimson, inexperienced, and blue colours, however you additionally see the secondaries and all of the ranges in between. The middle is white (as a result of it’s essentially the most impartial half) and as you progress away from the middle you’re introducing extra saturation within the path that you just’re shifting your corrector.
The colour harmonies wheels present the connection between the colours. If you have a look at the colours which can be subsequent to one another on the primary wheel, they’re stated to be analogous colours which can be harmonious as a result of there’s a pure falloff from one hue to the following.
The colours which can be reverse one another on the colour wheel are stated to be the complementary colours (additionally known as contrasting colours) as a result of while you put them subsequent to one another in a scene they complement one another to make the colours pop—which is how we create colour distinction in a scene. The subsequent one is the monochromatic wheel, during which you keep in a single hue however change the depth of it.
Hue refers to totally different colours or totally different shades of colours, saturation refers back to the depth of the colour and brightness refers back to the luminance of a picture. If you take away the chroma (or colour) of a picture, you’re left with the luminance data, as you possibly can see on the grayscale chart.
Display applied sciences
[14:10] We subsequent lined show applied sciences, utilizing an LCD monitor. You can consider an LCD monitor as a type of “glass sandwich” that consists of quite a few layers: a backlight that emits a white mild calibrated at 6500 levels Kelvin, plus layers that include liquid crystal materials, polarizing filters, and tiny transistors that inform the pixels to what diploma they need to be turned on or off.
On the monitor there’s a direct relationship between your luminance and your chrominance or your saturation. If you’re growing saturation you’re principally intensifying these RGB pixels and fewer backlight can get by way of. Similarly, while you’re growing the luminance channel you lose some saturation as a result of extra mild will get by way of these pixels and dilutes these colours—so that you need to be aware while you’re making one adjustment to compensate for the opposite.
SDR and HDR
[15:45] What we do as colorists doesn’t actually change by way of the method whether or not we’re working in SDR (Standard Dynamic Range) or HDR (High Dynamic Range). HDR gives us a bigger palette or canvas during which to work with a wider vary of perceivable colours and distinction.
In SDR, the content material is mastered to Rec. 709 colour gamut on a 100 nits (the measure of luminance on the display screen) mastering show and is then encoded in Gamma 2.4. One of the elemental points with SDR is the shortage of management over the white luminance on display screen. For instance, within the case the place you have got a decrease third in your display screen that’s white, that decrease third has now grow to be the brightest factor on the display screen—as a result of white is outlined by the utmost luminance on that gamma-encoded content material.
As we transfer from SDR to HDR, we’re shifting from the Rec.709 gamut to D65-P3 gamut and mastering that in a Rec. 2020 container—which is even bigger than P3. This future proofs the HDR mastering commonplace for when displays grow to be absolutely able to displaying the Rec. 2020 gamut.
Additionally, HDR content material is mastered in ST.2084 as a substitute of Gamma 2.4 at 1000 nits of luminance (ST.2084 is also called Perceptual Quantization or PQ for brief). This mixture permits for assigning code values to the luminance ranges, which not solely permits elevated distinction and a bigger colour palette, but additionally gives management over how shiny whites might be on display screen. In HDR, with the next dynamic vary and D65-P3 colour gamut, you’re capable of create extra depth in your picture that provides you a extra practical look with extra artistic management.
Now, should you apply the identical decrease third in an HDR house, you’re really capable of assign a code worth for a way shiny you need that decrease third to be (say, 200 nits). That will get encoded into your closing render so when the sign reaches a tv that’s able to displaying at 1000 nits it might probably learn that worth and is aware of how shiny that white is meant to be. Eventually we’ll attain the purpose the place all shows are able to displaying Rec. 2020 and can grade all our content material within the Rec.2020 gamut.
Beginning the grade
[20:23] Since we’re speaking concerning the fundamentals of colour, one of many subjects that it appears isn’t addressed typically sufficient is colour psychology. We cowl it briefly on this session, however I additionally encourage you to learn extra about it for yourselves as a result of not solely is it fascinating, it’s additionally important data for successfully capturing a director’s artistic intent and conveying it to the viewer.
Colors can evoke totally different feelings in us. For instance, if you wish to convey a way of tranquility, you wouldn’t select the colour crimson, which is related to hazard. Instead, you would possibly select shades of blue, which recommend water.
[22:36] The level is that colour grading is an extension of cinematography, and the colorist is chargeable for understanding the story the director and cinematographer have tried to seize. Every video, whether or not it’s a function movie or a company video, has a narrative or a sense that must be conveyed, and that’s after I apply my data of colour psychology to reinforce the artistic intent.
When I begin grading a venture, I start by trying on the offline dailies. A primary colour correction can have been utilized to them and that’s what the workforce has been working with all through the edit. I ask for the LUT they used, and take note of the manufacturing design and lighting. I speak to the filmmakers and ask questions to higher perceive what they’re hoping to realize.
“Talk to the filmmakers and ask questions to better understand what they’re hoping to achieve.”
Maybe the story is about somebody who’s operating away from darkness and on the prime of the mountain is freedom. I’d need to have two colour palettes—one for the darkness, which has cooler undertones—after which one for once they attain freedom. I modify my general corrections to stick to the story after which immediately, although we began with the identical LUT because the manufacturing, we’re already at a a lot better place.
I begin my course of that approach and now have another LUTs and presets in my toolbox, and I encourage you to avoid wasting totally different presets and totally different seems to be that you just’re creating. It’s additionally good to make buddies with colour scientists and different consultants and colorists within the trade.
Once you dial in that preliminary look, you possibly can audition it with the filmmaker and gauge their response to see should you’re headed in the suitable path. There are, in fact, circumstances the place the filmmaker needs to alter the look of what’s been captured for no matter motive—it could be that they shot in lower than superb circumstances or perhaps the story has advanced in a special path. When that occurs, it’s higher to not give them a glance that’s too excessive initially, as a result of that may result in them shedding belief within the course of.
What’s a LUT?
[28:46] If you’ve come this far and need an explanation of what a LUT is, it stands for Look Up Table. We may do a complete session simply on LUTs, however briefly:
Modern cameras that shoot in Log format are designed for the sensor to seize as a lot data as attainable, however that seize format must be processed so as to be displayed appropriately. So while you have a look at these Log recordsdata straight in your monitor, the video seems to be washed out.
A LUT is a translator of kinds. It takes the enter worth from the unique digital camera file and transforms it to an output or show worth. If you’re Rec. 709 Gamma 2.4, an acceptable SDR show LUT to your kind Log or Raw recordsdata converts your footage successfully from that Log format to one thing that your show is able to displaying so that you’re monitoring it appropriately.
Most digital camera producers present primary types of LUTs for his or her Log codecs which you could obtain as your start line for viewing, that are known as conversion LUTs. There are additionally artistic LUTs which can be designed to present you a selected look. For instance, you possibly can obtain a LUT that may give your movie the appear and feel of a Ridley Scott film, or provide the very talked-about orange and teal look that’s utilized in so many motion pictures and exhibits. Let’s simply say that while you begin entering into that territory, there are some superb LUTs—and a few dangerous ones.
Lumetri demo
[32:05] Here we get into the demo of the Lumetri panel. First, I exhibit the right way to entry the panel and present you ways I prefer to arrange my workspace.
Some of you requested questions on what sort of monitoring is required, and should you’re severe about correct colour grading, it is best to put money into a broadcast-quality monitor. Adobe gives a list of recommended hardware here, however you can get an AJA or Blackmagic video card that offers you an accurate broadcast sign out to your grading monitor, which is the one you depend on for judging your colours.
[35.15] If you’re in your GUI monitor (I used to be utilizing my Mac in a p3 house however my broadcast monitor was set to Rec.709) there are variations between the 2 and also you need to guarantee that each displays are in the identical vary. You can do that by going into the Premiere Pro settings and enabling Display Color Management, which provides a small tone mapping so I can see a comparable picture on each displays.
There’s quite a bit to debate about monitor calibration—a lot, actually, that we’ve determined to host an upcoming session that covers displays and scopes.
At 36:02 you possibly can watch as I construct adjustment layers and see how I maintain my layers organized. I attempt to restrict what I’m doing in every layer so I’m not doing too many corrections in a single layer, and I label them in order that when you have got a extra advanced timeline and also you’re copying and pasting grades you possibly can simply know which layer is doing what.
Beginning at 37:01 I exhibit how I added LUTs, after which go on to do some primary changes for colour temperature and publicity. At 39:33 you’ll see how I take advantage of the Frame.io panel to obtain a reference body that exhibits how the director needs the background colour modified, and the way simple it’s as a result of I don’t even have to go away Premiere Pro to entry it.
After that, I exhibit how I evaluate the reference to the clip I’m colour correcting in a side-by-side view. Note that I’m making my corrections on a LOG clip after which sending that corrected sign to my adjustment layer, which converts it to Rec. 709. This is named scene referred or enter referred colour correction.
Then, at 42:45 we focus on scopes. I like to make use of the RGB parade and my vectorscope, which breaks down the first colour channels and provides me a fast view of the right way to steadiness my picture, whereas the vectorscope shows saturation. And at 44:14 you possibly can see the road on the vectorscope that assists in balancing for Caucasian pores and skin tones.
At 45:24 I present you the right way to obtain the director’s desired purple colour by utilizing curves. Another factor I prefer to you should definitely do is to not simply give attention to a nonetheless body, however to play the clip so I can see how the correction seems to be all through. At 47:57 I present you the right way to work with curves in luminance and within the RGB channels.
At 49:07 you’ll see how I add some mid-tone element utilizing the HSL (hue, saturation, luminance) secondaries with the eyedropper tool. Then, at 50:33 I take advantage of the luma channel corrector slider so as to add a bit extra distinction.
At 51:04 the vignetting is a bit heavy so I’m capable of take that down a bit utilizing the vignette tab. And then, at 52:09 I present you ways I copy the grades I’ve utilized to my first clip and apply them to the second clip, which is sort of comparable. Finally, at 53:11 I’ve a brand new clip in a really totally different setup. The LUT they utilized throughout editorial provides us a delightful picture, however the filmmakers wished to convey extra life into the picture and create extra distinction. So there I deconstruct the ultimate look I’ve achieved and present you the steps I took to get there.
Q&A
At 57:05 we start the Q&Part of the session. The first query was across the significance of getting the suitable {hardware}. To recap, as a result of it’s so essential to have the ability to watch clips in movement, having {hardware} that helps watching the full-resolution clip because it’s going to be mastered is significant. Without that means you’ll should view a decrease decision picture, which is lower than superb. That stated, there are actually many inexpensive techniques that can be ample for enjoying again high-quality, high-resolution video.
[58:19] The subsequent query lined the right way to white steadiness so as to have essentially the most management over your footage in publish. The particular person asking the query has used auto-balance, which has yielded blended outcomes. It’s why, in the course of the demo portion of this session, I lined the methods you possibly can manually manipulate the picture—as a result of should you’re utilizing auto settings, you find yourself having much less management.
The rule of thumb is that you just need to maintain your lighting values as constant as attainable when capturing in comparable circumstances. But, there’s an eyedropper instrument in Lumetri for white steadiness. If you have got a reference in your footage of the white that you just’ve derived from an auto steadiness and it seems to be proper to you, you possibly can merely seize the eyedropper and choose it, which routinely then makes changes to your temperature and tint and provides you a superb begin towards a delightful consequence.
[1:00:13] We had a couple of questions on displays, questioning whether or not getting a monitor with pre-built colour profiles akin to an correct Rec. 709 is price it, or is calibrating a greater choice?
It’s an essential query. So, one of many the explanation why we use these costly displays and reference displays is as a result of we need to see the imperfections of the picture. A shopper monitor has built-in options like noise discount and you probably have noisy footage and also you’re judging it on a monitor that masks these artifacts, you assume your picture seems to be good and then you definately render that out and..it doesn’t. So you want a correct monitor that’s displaying you all of the imperfections.
There are skilled calibrators which you could rent, and it’s also possible to purchase totally different units like a C6 probe and put it in your show to see if it’s correctly calibrated.
If you don’t have a broadcast monitor and you could depend on a pc monitor I feel an important factor is to attempt to persist with one ecosystem. Apple, for instance, has a stage of consistency even of their mid-range units, like iPads (that are able to very high-quality HDR shows).
In closing, it’s essential to correctly calibrate your displays should you’re doing skilled grading. And, once more, we’ll plan a separate session protecting that subject!
Meanwhile, thanks for listening and studying. I hope you’ll be part of us for the following session on August 23 at 1pm ET for a demo with Brandon Heaslip of Colorfront. Stay up to date with our Frame.io Live events right here.
