What is SUBTRACTIVE Saturation!?! - Pro Colorist Masterclass - Film Emulation in Davinci Resolve

in this video we're going to discuss subtractive saturation what is it how does it work why is it considered filmic what's the easiest way to apply it to your images to understand subtractive saturation we need to understand film as this side of the New Millennium most people's journey into cinematography begins with digital it's a common misconception that film mirrors the way that digital camera Works let's clear that up there's two ways of producing color additive color and subtractive color first let's talk about additive color imagine you have three lights pointing at a white wall one light produces red light the other produces blue the final one green these three primary colors mirror the way our own human Vision Works when all the lights are turned off I get black if I want to produce white I Turn All the Lights On if I want the wall to be blue I only turn on the blue light if I want yellow I'll turn red and green on by adding additional light to the scene it's possible to mix different colors that's why it's called additive color it's how a digital camera works with its Bayer pattern sensor each time the camera records a new frame the photo sights start black and gradually collect more light the final image is an additive mix of red green and blue light that the photo sites have collected it's also how a project or monitor works by varying the voltage delivered to Tiny subpixels differing amounts of red green and blue light are mixed to create the desired color subtractive color works the opposite way instead of adding more lights to produce color we'll start with a clean white light and then subtract unwanted wavelengths until we're left with the color that we want we can do that by placing filters in front of that light source like a colored gel or by putting pigments paint on the wall that absorbs select wavelengths of light while reflecting others by far the most common primary colors used with the subtractive color system is cyan magenta and yellow why because these colors are the exact opposites of red green and blue it should be noted that a perfect yellow paint would absorb every frequency of light except perfect yellow in reality though it's more accurate to say that the pigment's most reflected color is yellow and its least reflected color will be blue the opposite of yellow the same would be true of a yellow filter that's why it appears yellow but still contains other wavelengths of light I can make the wall appear blue with an even mix of magenta and cyan paint both pigments allow blue light through but cyan is good at absorbing red and magenta is good at absorbing green if I want the wall to be black then and even mix of every color will absorb most of the spectrum that's the theory real life is a little bit more complicated though a really good example of subtractive color at work is anything that's printed like a newspaper for example you read your newspaper in clean white light and on the paper carefully arranged cyan magenta and yellow dots selectively subtract colors as the light bounces off the paper and travels to your eye film is also a good example of subtractive color at work film has cyan magenta and yellow dye layers now did you know that cmy layers not RGB now whether scanning or projecting when you shine a clean white light through your developed film each layer subtracts frequencies or colors from the clean white light to produce the colors that you ultimately see why does this matter because additive color manipulates Colors by adding more light it makes colors brighter subtractive color takes light away making colors darker let me show you what I mean let's say you've shot a beautiful blue sky on film The developed image will have an incredibly strong magenta and cyan record when talking about film we call this density the more intense the blue sky was the denser that part of the negative will become and the denser the negative the less light it will allow through when scanning or projecting additionally as film approaches overexposure it starts to become less sensitive to light that sounds like a bad thing but it's what actually gives film its incredible dynamic range and attractive highlight and saturation roll-off let's briefly compare that to the way a digital sensor saturates in additive color the stronger the Blue Sky becomes the brighter that portion of the image becomes if enough blue light falls on that part of the sensor it can completely saturate and overwhelm the blue photocytes causing clipping even if that's only on one channel there's no roll-off like you get on film just a cliff Edge as a result many people still consider film like saturation to be more aesthetically pleasing than the way that digital cameras render highly saturated colors filmic saturation is the gold standard the native saturation controls in DaVinci Resolve apply additive saturation as a result if you overwork this control you can create an unpleasing image so here's three ways to simulate subtractive saturation in DaVinci Resolve a fake way a simple approach to replicating the effect of subtractive saturation is to make a given color darker this can be done globally by reducing gamma or a specific color can be targeted with a hue versus luminance adjustment or finally highly saturated colors can be targeted with a saturation versus lumor adjustment as you can see this looks particularly bad some of these methods worked better than others all three methods share similar problems reducing gamma darkens the entire image not just saturated colors Hue versus saturation also globally desaturates all blue regardless of whether it's saturated or not and can also create artifacts where one color transitions to another and finally a naturalistic image is hard to achieve with sat vs Luma again because it desaturates unwanted parts of the image too I'll save a version of this grade with my best effort so we can compare it to other techniques later it's possible to create subtractive saturation in resolve without any paid plugins but it's complicated this technique is based on a method outlined by Cullen Kelly in his mixing line article there's a link in the description but please note we've made a few tweaks to the technique manipulating the image's saturation subtractively requires us to separate the image's saturation from its luminance color models like hsl and HSV are great for this because they have channels dedicated to saturation and brightness in this instance HSV is the model of choices when using hsl voluminous value affects the saturation of the color at its maximum values hsl produces white however at hsv's maximum values it produces a fully saturated color create a new node right click and set its color space to HSV that means that this node and this node alone will Now operate in a different color model than all the other nodes now my primary controls instead of manipulating the image's red green and blue channels will manipulate its HSV values now R manipulates hue G manipulates saturation and B manipulates value I only want the value or brightness Channel reducing the gain for the red and green channels gets rid of hue and saturation and leaves us with just value I'll create a layer mixer and just tidy up my node tree I want to feed an unaltered copy of my image into the first input it's not strictly necessary but I'll create a new node with no adjustments just to keep things tidy and feed it into the first input of the layer mixer and then feed my V node into the second input let's just connect my node tree back up to the output by setting the composite mode of the layer mixer to subtract I'm effectively taking away all the brightness information from the image and leaving just color this leaves me with a black screen there is still information there but because of that subtract operation the pixels have negative values that's why it shows us black but of course that information is preserved as resolve Works in 32-bit float now I'm going to add the V value back to that black image that's the very value I subtracted from it in the first place I need to create a node to do this partly because you can't feed a layer mixer into a layer mixer but mostly because I'm going to use this node shortly for my subset operation don't forget to change the composite mode of your second layer mixer to add it's undone what the first layer mixer did if your image looks like it's not changed then you've done the right thing what's the point of all that work to end up with the exact same image we needed to set all that up so we could do this when I manipulate the gain control on this node it adds subtractive saturation to the image we can confirm that by looking at the Scopes when I add saturation by increasing the gain the Scopes show my red green and blue traces are decreasing in brightness for reference let's compare that to additive saturation I'll reset my gain operation and just use the vanilla saturation tool you can see that when I add saturation with this tool the traces in my scope rise I much prefer the subsat look it feels deeper and more pleasing to look at I'll reset and once again dial in some subtractive saturation with the gain tool as blue is the most dominant color in this image I'll focus on what this tool does to the blue Channel you'll notice it adds saturation by decreasing the red and green channels the blue channel is Almost static it doesn't move it looks very pleasing and unlike our previous attempts darkness and color casts are not added to unwanted parts of the image the subset operation is confined to the parts of the image that were already strongly saturated is simulating the way that film saturates the stronger and brighter a color the denser and that's darker that part of the negative becomes a qualifier can also be used to limit saturation operations to a particular color range in the image for example I enjoy the effect of the subtractive saturation on the sky but not on the model's skin or strongly colored jacket it's difficult to create qualifiers on the subsat Node as thanks to our mathematical Shenanigans it's got negative values That's why nothing shows in the viewer or on the Scopes instead I'll create a branched node and use this to build the qualifier let's do some housekeeping and name the node qualifier then connect it to my node tree I'm sourcing a clean copy of the image qualifiers are easier to build with the Highlight mode turned on so I can see what I'm doing I will eye drop the sky and tweak the Hue qualifier it's looking good let's pipe that key we just created by connecting the alpha output of my qualifier node to the alpha input of my subsat node now that subset operation is limited to the Blue Sky in the image that looks much better I'm no longer getting that over saturation on the skin and red coat once again a big thanks to Cullen Kelly for detailing this method in his mixing light article again I'll save this grade as a version so I can compare it later but wow that was complicated it's doable but complicated these notes can be compounded but then it's no longer possible to manipulate the saturation effect which will be buried inside and setting this up on each shot that you have to work on even if you use power grades is going to be a pain so be ready for option three dctls provide a framework for developers to augment DaVinci resolves functionality several developers have made plugins for subtractive saturation and we're looking at one Hue shift by pixel tools instead of building out complex node trees or using inferior methods I can now apply subtractive saturation with a single node installation is super easy Once purchased just place the dctl in the correct folder within your resolve installation inside the color page apply the dctl effect to a node and then select Hue shift from the drop down the tool offers independent Hue saturation and density controls for red green blue sign magenta yellow and a final special control for skin tone there's some additional controls here too that we'll explore shortly let's add some subset to the Blues in my image I can confirm that this is subtractive saturation by looking at my Scopes you can see that as I add saturation to the blues my blue parade is not increasing in fact it's not moving at all instead my red and green traces are lowering this tool has been developed by two names that you might know Jason bodak and Carl Hendrickson I'm loving using this tool instead of me doing a bad job of explaining how it works how about we ask them and get some of their insights I'm Jason bodak and I'm the founder of pixel tools and the co-developer of the Hue shift dctl can you tell us why did you make Q shift what problem is it solving my purpose of creating Hue shift was an easy utility that you can adjust the Hue the saturation and the density of any Hue and it goes really smoothly I'm a big fan of sticking in the creative mindset and I have problems when you have to go okay there's a technical problem I have to shift mindsets over to my technical mindset and then back to my creative and I wanted it to be really easy for colorist to just I want to shift my Reds over here I want a more true red or I want a more purplish red I'm a big big fan of Shifting greens over to teal as a lot of people are and I want it to be really really easy to just here's my green water I'm going to shift it a tiny touch towards teal and I'm going to make it a little bit darker and then move along without having to shift your mindset over to a technical mindset can you give us an explanation of what density is and why that's so important to your work as a colorist density is a really popular thing now it's a very important part of film emulation and it's essentially the luminance of a hue now it's not just the luminance but it gives that deep feeling that deep tone a lot of people when they're creating film emulations I'll add grain they'll Appalachian they'll add the contrast curve of a specific film emulation and they'll look at it and they'll go why does it not feel like the films that I've seen shot on Kodak Vision 3 Kodak whatever film stock you're doing and usually what they're missing is the density of those Hues essentially the colors shift non-linearly throughout the entire dynamic range and that's why film is so unique and I wanted to make a tool that added a little bit more Nuance to that is density something that's only relevant for a colorist that's grading a film emulation it's important to remember that we've been looking at film captures for over a hundred years so it's something that we're used to seeing so even if you're not trying to emulate an exact film stock it's important to remember that we have been seeing stuff captured on film for in excessively long time we feel it deep down inside so it's important to remember that density is a tool that we can use to lean towards a natural look that we are more comfortable that we are more familiar with one of the things that I like about adding density adding subtractive saturation to an image is on the spectrum of emulating film I'm going to put duh scratches Sparkles I'm going to put a little bit of gate weave on there I'm going to maybe emulate a print stock that's quite in your face but I feel like subtractive saturation is a very important element of the film look but by just selectively adding that and that alone to an image it puts it in this really nice Middle Ground where it's like there's something rich and deep about this image I call that modern film emulation in the fact that we are taking best aspects of film which is adding what we want from it which is the density which is the Hue which is the contrast curve and not using the aspects that we don't want which might be the noticeable grain which might be the gate we which might be the dirt and scratches so this is really cool Jason explained his grading mindset that influenced the development of this tool for me color grading is best used as an art that is unnoticeable we don't really want our audience to notice that it's been manipulated in a way the best thing you can tell me is to notice that you know that was a beautiful looking film I really felt the narrative I was really sucked into it but where was your work and to me that means that I've done my job perfectly I specifically uh started my development on Hue shift because I felt limited and I felt I was spending too much time in the UV curves and the color worker and I wanted a simpler easier method to adjust the Hue saturation and density so if you are having similar feelings I would recommend checking out the demo of fuchsia and seeing if it improves your workflow I feel like it boils down the difference between eight nodes or one node exactly and I was one of those guys who had these massive power grades and compounds nodes to do things like density but then especially as you get down to I want to have density for teal I want to have density for uh blue and red and being able to quickly manipulate those especially on hundreds fifteen hundred shots eighteen two thousand three thousand shots it gets to be very overwhelming and then when you go back to that consistency I want it to be the same way on every single shot so I wanted to make almost what looked like a tool that was built natively for resolve that enabled fast adjustment and I wanted it to work on a panel needs to be efficient it needs to be fast and it needs to flow quickly we got to speak to Car 2 so Jason's divisionary and car he's equally as Visionary but in this instance he's the developer that programmed this dctfl Hendrickson and uh I'm with a guy who made the tool Jason reached out seeing how seen my different DC tails that I've made and and found that well having so many different digitals in a new tree is kind of cumbersome and he'd like to combine many of them into a single tool and that's how you shift or spawn let's get core's explanation of density and subtractive saturation too so in contrast to usual saturation which tends to add to that RGB channels subtractive saturation Works where we're trying to achieve more colorfulness if you may by taking away from the RGB channels so what is the advantage of doing it with the dctl rather than just brute forcing it yourself the main advantage of using this digital over just doing it manually is just ease of use where instead of building these whole huge node trees and then finding the right node to change the saturation and then you know it's a whole mess you just have a single slider that works there are a bunch of other controls in this dctl Carr kindly explained what they do the Deep slider is actually just a simple key qualification of highlights where if you're applying saturation and you find that it's targeting colors in the lighter parts of your image that you don't like and don't want to change then you can just apply the Deep slider and it'll leave them put so the sub add slider or subtractive additive slider allows you to fade between the subtractive saturation model or mode and the attitude mode to see which one looks better for your image the density slider is actually modifying luminance based on saturation so it isn't trying to add any more saturation but it's trying to make very saturated colors darker making them kind of deeper in that sense and with the built-in qualifiers we have made it where if you add all of the qualifiers together you get the whole image so you have control of every single Pixel but in a very smooth way where it's quite difficult to break the image this digital also includes Hue shifting and the interesting thing about it is that instead of using hsl or HSB that will most tools use or if you're doing it manually you would use we are using the Chen spherical model please definitely go check out Jason bodak's websites and cow's Awesome YouTube channel links are in the description I hope you found this video helpful if you'd like to try out or perhaps buy Q shift yourself there's a link in the description it is an affiliate link so if you make a purchase we'll get a small commission it's not much but it helps support the free content that we create at Team 2 films a big thanks to Jason and Carla for their work on this tool and the time that we spent chatting we've got some other thanks to Colin Kelly for his mixing light article detailing the manual process for subtractive saturation Daria for soon for all the groundwork that she's done any journey in the color page always starts with the things that I've learned from her and Darren mosten also has a great video out on subtractive saturation it's informative and well worth watching if you enjoyed this video please give it a like And subscribe so you don't miss out on future videos thanks for watching [Music]

Channel: Team 2 Films

Views: 77,748

Keywords:

Id: r5MZN0MdlY8

Length: 20min 54sec (1254 seconds)

Published: Wed Sep 27 2023