Perfect NR In DaVinci Resolve - BBC TV Colourist Insight (Noise Reduction)

so my last episode was all about making the perfect no tree and this caused quite a stir in the comments I had hundreds of comments from people going where' you put halation where'd you put glow where'd you put your grain why you putting your grain there and not the beginning all this sort of stuff but the most common thing that kept coming up was where did you put noise reduction and it made me realize I haven't actually done a single episode about noise reduction at all I'm going to show you exactly where noise reduction goes I'm going to show you two different examples actually because I don't put it in the same place religiously on every single program I'm going to show you why I would change where it goes in the notary I'm also going to show you a couple of really good tips on how to dial in exactly the right amount of noise reduction and to do that I've been very kindly allowed to use an actual bbc1 documentary that I worked on in June it's called Tommy Jessup goes to Hollywood I'll put a link to it in the description and Tommy's brother will is actually the director of work with him a couple of times now and he's very kindly let me use the footage from that to show you a real world example so let's get straight into it so this is the actual original project that I worked on you can see my node structure is very similar to what I gave away in my last episode and this is a 1 hour BBC documentary so let's have a look at how many shots that would be so looking in light box I've got all Clips selected and it's 661 which is very typical for a 1our documentary The reason I'm pointing that out is because I don't use noise reduction unless I really have to I don't like using noise reduction it's as simple as that if I filter this by noise reduction you can now see how many Clips I've actually got noise reduction on and it is 56 so it's less than 10% of the program has got noise reduction on it and you can see quite clearly some of this stuff is very low light this is a sort of fly on thee wall type documentary uh a lot of run and gun shooting so you're obviously going to get scenarios where the lighting is not perfect so that's mainly why there's noise reduction in here so to allow me to explain the different techniques of noise reduction I've chosen two very specific clips from the documentary and I've put them into a separate timeline so let me just show you what that is about I've got a shot here and let just quickly scrub through that and I've got a shot here and they both have different noise reduction properties and they're in different places on the timeline so you can see this one is on node 2 and the previous shot the noise reduction is actually on node three so I'm going to explain why that is happening so let's take this first shot here and let's have a look at what's going on now just to show you a quick bit about the color management that's going on here if I go to my settings go to color management we're in our regular D Vinci wide gamma intermediate timeline color space and our output color space Rex 79 gamma 2 .4 and we're using csts for our color management okay all documented in that episode last week I've got one on the end here this is taken as D Vinci wide gamut to 709 as always and our front CST is our camera profile up to D Vinci wide gamut and the camera profile on this one is Panasonic Vlog okay so it's Panasonic camera what I want to show you first is how it looks but with the csts on so it's not the log image I'm going to show you it's in the correct color space and you'll see what's going on so I've just got to wipe here this is the image as you can see it's really underexposed and so the first thing I had to do was lift it using this node here okay that's a lot of lifting to do in there because it's underexposed you've got noise and I've had to lift it a lot so this is why I've put the noise reduction after this node in this instance okay normally I would have it after the CST straight away but this one needed so much lifting that I've actually put it in third I wanted to lift the image up first now if I switch this noise reduction off you will see how much noise is in here let me just zoom in a little bit for you I'll zoom in 200% and you can see see a lot of noise in here okay so let's have a look at what I did for this shot I'm going to put it back to uh fit and I'm going to bring up a couple of Scopes here so we're going to have our parade and our Vector scope going on and let's just switch that on and off you can see quite clearly the noise even in the scope so what I'm going to do in this is I'm going to reset that noise reduction I'm going to build it from scratch so on your Scopes make sure that you don't have this selected it's a low pass filter and what that does is filter out noise on the scope so we want to see the noise on our Scopes is our first first tip all right and then what we're going to do is come over to here so we've got our motion effects so this is just selected from here this row here and we've got two different types of noise reduction we've got temporal noise reduction and spatial noise reduction motion blur on the end here is just in that category it's not noise reduction at all it's just a it's literally motion blur so it sometimes you can help disguise it but it's not part of noise reduction so temporal noise reduction is looking at um forward and backward frames in time so what it's doing is taking a a single frame that you're on and depending how many frames I select here up to five will depend how many frames forward and backwards it looks at changes in the shot thereby determining what could be Noise Okay now once you go above three into four five your system literally will grind into a hole okay it's really really slow performance I've got a really fast Mac here when I go into four or five frames temporal noise reduction my system pretty much grinds to a hold I generally start start at two and often will'll just stick at two I want two frames forward two frames backward so the motion estimation type is faster is obviously going to give you uh faster rendering but slower results and we always want better we always want the best results so no point in putting that on to faster at all and the motion range here is saying how much motion is actually in the shot itself so if I just put this into Loop plate and then we just start playing there's not actually a lot of motion going on in this shot so what you're doing is helping the temporal noise reduction know how much movement should be in a shot so if you're in a whip pan obviously that's a lot of movement okay so we'll just put that to medium so there's not actually any noise reduction applied yet because these figures here luminance and chrominance are still set to zero okay by default these are linked together so as we start moving up we start introducing noise reduction and you can see that's going much softer already and let's take it back off and we can see the noise now one thing I do with this is I keep an eye on the Scopes all right so watch this is our RGB parade so it's the red green and blue channels and this is Vector scope which is our saturation and I'm going to unlink these so the first thing we going to do is dial in temporal noise reduction in the Luma Channel and let's just look at our scope and see what's happening so as I move that you can see there's a point at which if you look around here there's a point at which it takes out the noise and then it doesn't do anything anymore so that would be a good point to start at you just find the point where it kicks and then just come back a little bit let's have a look what's happening with the chroma okay there a little bit in the shadows there as I'd expect okay so just down in the shadows that is being affected okay but not so much in the highlights there so somewhere around about there so let's leave that set for there for now the motion here is this is helping with aliasing and artifacts that you might get on the image when temperal noise reduction is applied so you can adjust that higher or lower amounts of motion and the blend is obviously blending it back to zero so if I have that back to on 100 I've actually effectively taken the tempal noise reduction off all right let's have a look at spatial noise reduction what spatial noise reduction is working on a frame by frame basis so it's much more accurate than the temporal noise reduction it's literally analyzing the image and it's trying to keep as much detail as it possibly can so it's a far more intelligent noise reduction but again this is much more processor intensive so you've got your faster mode we don't want to work faster okay we want to work at least better the radius is the amount of softening or blurring if you like that the spatial noise reduction is going to apply High to the image so we want to keep this as small as possible so start with small if you need to build it up we can go higher so next we've got the threshold for our spatial noise reduction and Luma and chroma are actually locked together this is because we're in better mode you need to go to enhanced mode in order to make them run independently now a quick tip here is that if you go up to the effects you've actually got noise reduction as one of these open effects and the reason for that is it now works in the edit page as as well so it needs to be in this column so you can grab exactly the same settings that you've got here in your open effects let me just type in noise see if we can find it there it is I'm just going to put it onto a blank node for the minute so you can just see the menu but what's nice with this one is if I go to spacial noise reduction and go to better I can actually separate luminance and chrominance out so if you need to do that but you just want to look in better and not enhanced you should use it using the open effects and in fact sometimes I get better quality from the better mode than in enhanced mode so it's worth playing with both the main reason I'm not using it as an open effects all the time is because I'm on the advanced panel and it's really really quick to dial in noise reduction on the panel so what we're doing now is just having a look at how much temporal and how much spatial to put in and ideally I want to be working with spatial a bit more than temporal so I try and get them to about a half split so whatever I've got going on in spatial I'll try and sort of work on measurements around about half in the tempal don't go exactly half but somewhere around that sort of ratio so we've been using our parade and our Vector scope at the minute if I just switch that on and off that Noe we can see it's definitely reducing noise reduction and let's just zoom into the image let's have a look at what's really going on here it's his face that is concerning me quite a lot in here we want to make sure that that doesn't look noisy if I play that in a loop okay you can see with that noise reduction on it really did need noise reduction in this instance okay I avoid it like the plague but I did actually need it here so let's just put it back on and I just don't want to go too heavy I don't it's a little bit of a soft shot anyway but I don't want to overdo it so let's just dial in a little bit more spatial threshold and just see what we can get okay now the second tip I've got for how much to dial in is coming away from the Scopes so again we're just checking that it's actually affecting it okay that's not really affecting it much there in fact if I take my temporal threshold down a bit more let's see if I can actually reduce it better using spatial threshold yeah there's a little bit coming in there so if I put my chroma there and my Luma there I'm just playing around with these but what I'm going to do is switch to a different mode and if you go up to your highlight tool and press AB what that does is show you what you're doing just on that node okay so if I switch all my noise reduction off let me just do this brutally there's nothing appearing because we haven't actually done anything so let's go back and dial in our settings again we're going to go two we're going to go better we're going to say at medium and we're just going to dial in just Luma and there we can see what's being affected let's put a little bit of chrome in there and let's go to our spatial let's start with better and small and I'm just going to dial it in and what I want to do is keep dialing it in but protecting the edges of his face okay so they're the main features we want this noise here taking out but we don't want to be in a position where we're seeing like this this means we've got very heavy noise reduction going on so I'm just going to di that back again and I'm just going to go until we can just see his face and I'm going to knock it back a little bit and just by default we seem to have got so that's 27 28 so half that would be about 14 so we're a little bit less than half let's just punch in a little bit more of this then again half is just a little rule that I've used and let's punch that back a little bit more switch the ab off oh sorry switch the Highlight off and let's have a look at how much noise reduction we got going on there so it's done a really good job of cleaning up the image but this is looking far too false now it looks a little bit plasticky so I'm going to dial it back we could use blend here but I'd rather actually dial back the amount of noise reduction then blend it back so something like that so let's have a look with it on so obviously we need to have it on it looks much better this is far too distracting for the viewer and we'll put it on it's doing a good job of clearing up here here and here okay let me have a look at the whole image and press play all right so that to me is looking much better than that you've got to always just put it on and take it off just check that you're actually improving the image we could add grain and sharpen and things like that to bring a little bit of that sort of grit back I've got it on the end here after the CST so I tend to work with my grain in Rex 79 and if I just switch that on and off you can see it affecting the Scopes but let's just see what it's actually doing to the image yeah it's just putting a little bit of texture back in just to show you my settings on that if I go to effects I've got uh grain strength increased and if I'm my Advanced controls I normally bring down the highlights a little bit I don't want as much grain in the highlights as I do in the shadows and midtones all right so that's that shot done now what I'm going to do is move on to the second shot and have a look what's going on here so this shot let me just show you the whole thing my noise reduction is on node two and the reason for that is if I just command d That's log obviously but the exposure was actually very good on this one it just happens to have picked up a bit of noise so if I disable that and play through the noise on this one is actually in a certain focused area and it was just a little bit distracting but if you look at his jumper and look at the camera even we can see noise in there okay can you see it and there's noise here okay and I just found it a little too distracting so I don't want a lot of noise reduction on this I just want enough to take the edge off that so let's put the noise reduction on and play that through and that's much better it's cleaned it up so what I've done with the noise reduction on this shot is I've isolated the Shadows into the midtones area and I've kept the highlights out of noise reduction so I don't want any noise reduction on his face his face is looking great there it's just a jumper and the camera that I really wanted affected so to do that I used a qualifier okay so before I reset this qualifier I have a look at Tommy's face here okay you can see it's got really good detail in it and if I reset this qualifier you can see that it's gone far too smooth okay it doesn't look quite as natural so let's rebuild the qualification that I did I used a luminance qualifier and I'm going to switch on my highlight I don't want to be in AB mode this time I want to be in this mode so I can see what's going on so I'm going to use the luminance qualifier here to protect the areas of highlight so just bring that down until it goes in y so we're just keeping his jumper exposed to noise reduction the camera here and obviously we need to soften that off or it's going to look really quite abrupt so something like that maybe I just knock that back a little bit so I'm trying to concentrate on what I'm doing and explain at the same time something like that let's have a look at what that looks like so I'm going to take that off I'm going to enable and disable so there we can see the noise reduction is nicely taken out his jumper and his face has been protected okay we just got a little bit going in there but let's just play it through always play noise reduction you really want to play it and if you're struggling to play this in real time what you can do is go to playback go to render cache say user right hand click on here and say node cache on and then that will now render so if I play that through it's going to start rendering it will go Blue once it's rendered there you go so now got real time playback of that noise reduction and anything I do after that this will stay rendered if I do anything before it then it will need to reender that cache okay that's a disadvantage of doing the node to late in the timeline so take a look at this video that's appearing here if you want a better breakdown of my perfect notary this is the notary I used on this BBC program as well look after yourselves and I'll see you in the next episode that was definitely a 10 out of 10 [Music] oh wied

Channel: Darren Mostyn

Views: 56,657

Keywords: Noise reduction, NR, davinci resolve tutorials, Davinci resolve

Id: vaVoyuAbB2c

Length: 15min 37sec (937 seconds)

Published: Sat Dec 09 2023