CONTRAST : S-Curve or Linear in Davinci Resolve

hello everybody today we're going to talk about contrast why contrast well because it is the most fundamental characteristic of an image it can make it feel Airy heavy or it can make it feel more digital or filming there are two main ways to add contrast to an image we've got linear contrast and we've got scurve contrast in this episode we'll look at what are the main differences between the two and also how I personally like to go about it without further Ado let's dive in all right guys so today we're going to talk about contrast and mainly the differences between linear contrast and esur contrast so what is linear contrast so to demonstrate that I'm going to go to my grayscale ramp and you see that I've got an ESC right here which is coming from my output transform so I'm going to disable it right here output color space I'm going to set to same as timeline if you want to know more information about how I'm set regarding color management I encourage you to see my color page Basics video that I did a while ago I leave a link down in the description so now you see that we've got a straight line and here is my my black point and here is my white point and I'm going to add contrast using my contrast slider right here you can drag here but I'm going to use my panel for that so there I'm adding contrast and there I'm subtracting contrast and you see that when I'm subtracting contrast I'm reducing the distance between my white and black point right here before it was there now it's there see so I'm kind of reducing that distance and that reduces contrast and if I do the opposite it adds contrast to summarize adding contrast increases the distance between the White and The Black Point and decreasing contrast reduces the distance between the White and The Black Point and now I can't talk to you about contrast without mentioning pivot right here and pivot you see that if I disable my contrast node before after you see that this value over here doesn't really get moved but now if I change my Pivot Point and I place it right here for example before after you see that it's rather this portion of my signal that isn't moving so you can change change that position basically when you work on your pivot so that is linear contrast because that straight line remains straight now we're going to explore what ESC contrast is so for that I'm going to go into my project settings right here and I'm going to go to my general options and see here there's use S curve for contrast and I have it unticked at the moment so look at what happens when I enable that and it save look at the grayscale ramp look at what happens to it boom then it becomes an S curve and you see that my black point position remains unchanged and so is the same for my white point and you see that if I exaggerate my contrast it'll look even more s shaped like so now if if we pay close attention to what the middle portion of our esur looks like we can see that it looks very similar that what we've got going on with linear contrast what actually changes is that now we've got a shoulder and a toe and the values are being compressed in the toe and the shoulder part of our curve okay so now we've discussed about the technical difference differences between linear and scurve contrast but let's actually see what happens on images so I'm going to reset my node straight line is back and I'm now going to enable my output transform I'm going to color management output color space and go Rec 709 gamma 2.4 and it hit save so we've got our S curve that is back but this is from our output transform so now let's jump to this shot and I'm going to add some escar contrast to this shot and I'm going to crank it before after before after and now let's see what happens to this image when I change to linear contrast I'm going to untick use escar for contrast right here and hit save look closely what happens to the image you see that the dark portions of the image and the bright portions of the image are getting more extreme it's getting a bit more crushed and it's looking less elegant let me switch back to es contrast so you can see it one more time I'm going to add save yeah there you go so see it's getting more elegant and looking a bit more filmy here now the reason why S curve contrast looks more elegant than linear contrast is because our top and low code values are being compressed in the shoulder and the toe of our curve so now that you see the visual differences between the two let me tell you what I prefer using and why so as a general practice I would use S curve contrast as a global adjustment and then if I have differences between the shots I would rather use linear contrast using lift and gain for example so if I want to reduce my contrast here I can do lift and gain see the difference before after before after but if I go to my timeline level and disable my contrast it's still there now to summarize I would say that I use esur contrast one time in a grade and usually that would impact all the shots in a scene and to correct for the differences shot to shot I would use linear contrast in the form of contrast and pivot or lift and gain for example all right guys that's it for today I hope that you found this episode helpful please leave a like comment down below let me know about future topics you would like me to cover come and say hi on Instagram and do not forget to subscribe to the channel to not miss future updates and I will see you in the next one bye for now

Channel: Douglas Dutton

Views: 4,944

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Id: oKzGkWhIisc

Length: 7min 39sec (459 seconds)

Published: Thu Jun 06 2024