Noise Reduction Tool Rawtherapee

welcome welcome welcome everyone to this Roth era P 5.8 tutorial today we're going to be going over using the noise reduction tool in Rock therapy now if you're anything like me your camera isn't that great and anything above an ISO of 800 probably gives you a lot of noise especially if things are still dark so I've gone ahead and chosen these pictures friend a couple friends and I went out to go take some pictures the other day and so I think this one looks pretty good now you can see immediately if i zoom into one to one and I go ahead and grab my hand tool that there is quite a bit of noise in here you can see I was really struggling I was at the max is zoom on my lens I had an ISO of 1600 and I was shooting at 140th and so there's even kind of some jiggle here that's causing some issues with the picture and that my aperture my lens isn't that great either so my aperture was actually wide open at 5.6 zoomed in to 55 millimeters so I think that this is the perfect image to go ahead and use but before we do that let's jump over to Rafi dia and I just want to point this out if you come to rob he da da therapy.com forward slash nose reduction they have this amazing introduction to what film noise is and where it comes from why it's there why we need a reduction tool so I'm not actually going to go through all of this I'm just going to point out a few points the first one is right here it says there are different tools for dealing with different types of noise and of course the north's reduction tool what we're talking about today is great for Gaussian or a Poisson noise the sensor read noise and thermal noise are best handled by the dark frame tool thermal noise would be where your sensor is getting too hot and so you start getting noise in your image and then salt-and-pepper noise where those black and white doc those are best dealt with with the hot / dead pixel filter and then the pattern noise is handled by the line noise filter and and I'm going to go ahead and just talk about two other things you can read this but I'm just gonna bring this up to you there are two different types of noise many types of noise one is chrominance and one is luminance now luminance has to deal with the light and the scene whereas chrominance has to deal with the color in the scene so we're going to be using kind of a combination of the both to get the best result possible okay so let's go ahead and jump back into Rock therapy now this image is dark to begin with so the best place to start is to look at our histogram to make sure that we're exposed correctly now there's a lot of darkness here of course but we can see that right here there's just a little tick up of this green meaning that we actually are correctly exposed actually we might be - one thing we could do would be to pull the black inosine down just slightly and I'm I'm doing that because before I could see that my values were ending on the histogram here at a value of one to be honest I don't know what that value is but I need to pull that back so that the green at least is ending at zero zero here so if I so if I pull back I've actually increased the lightness in the image without actually dealing with the exposure or the lightness anything like that just by pulling back on the black slider there okay so now I'm going to actually increase the lightness just a little bit and let's add some saturation and then let's jump before we do anything else over to the vibrance and as vibrant as well now I'm going to jump back into one-to-one here and we can see look at all of that noise and it's colored noise now one good thing we could do is jump over into the raw tab here and right here where it says censor with Bayer matrix and the D mosaicing we can change that from a maze down to lmmse if i jump back out to my full crop to see my photograph let me go ahead and redo that that same step here it's changes back to a maze see how dark it was and we're even getting some pattern noise here I don't know if you can see it but it's like there's a grid going across the picture and then we'll change this to lmmse and the reason that I'm doing that is lmmse D mosaicing method is actually better for dark photographs better for photographs that have lots of noise we're taking in a very dark high ISO manner so now that we've gone ahead and done all of those edits let's jump over let's go ahead and add some sharpening just whatever the base sharpening is add some local contrast to kind of tighten things up and now we are ready so let's go into the noise reduction tab now I'm going to turn on this little window here this is new to raah therapy it's the detail window so I can grab inside the window and drag this around anywhere I want and I can see at different different zoom levels so right now I'm at 100% a one-to-one if I hit this - I can zoom out if I hit the plus so I can zoom in of course if I'm zoomed to whatever and I hit one-to-one it'll go back to 100 and what I want to do is I want to put this window somewhere where I can see both light and dark and actually I think right up here in my friends hair let's maybe try over here is a good place to be we can see how much noise is there so let's see what we can do so there's two different color spaces that you can use when using the noise reduction tool of course if I turn it on nothing happens because everything is at zero now if I change from El El asterisks a Asterix B Asterix to RGB still nothing happens all that does is it you can see if I put my mouse over that for raw images RGB or la be methods can be used for non raw images only la B will be used regardless of what you do this is a raw image and I'm actually just going to leave this la b rd b is pretty standard when using the la b the l channel is for luminosity and then the a and the B would be used for chromaticity and then our RGB actually uses the CIE XYZ color space where the X and the y are used X minus y is used for the lumen luminosity and the X minus and the Y minus V is used for the chromaticity now for 99.9% of you none of that made any sense and that's okay because it doesn't really matter my recommendation to you is to just use the L a B color space now this is my favorite right here we have two different modes we have conservative and aggressive conservative is when you just have a little bit of noise that you want to take care of but here we have a ton of noise and it is bad so I'm actually going to change this mode to aggressive again nothing has happened because until I until I increase this luminous slider here no noise reduction will be applied to my photograph so then there's the gamma slider and the gamma slider deals with where the noise reduction will take place lower values will apply the noise reduction across a range of tones with an emphasis on the shadows whereas higher values will look more into the highlight so let's go ahead and take a look real quick now for the luminance I have here sliders and I also have a curve if you want to use the curve you're more than welcome I just find it simpler to use the sliders it feels a little more like Lightroom honestly and that was one thing I really missed about Lightroom so you do have more ability and control with the curve because you can add points giving certain parts of your image noise reduction and other parts taking noise reduction away okay so let me go ahead and just increase noise reduction here turn on the increase it up and now when I look at the main part of my image it still looks very noisy but if I look right here almost all that noise is gone so let me go ahead and zoom in a one-to-one and now we can see that noise reduction was super aggressive and it's gone ahead and blurred certain details for instance the around the glasses here and of course I put this up at a hundred which is quite high so let me go ahead and pull this back to something like 50 and then let me change the mode from aggressive back to conservative so you can see what that does now you can see automatically there's so much more noise on the conservative mode I move this to aggressive much less noise now detail recovery is exactly what it sounds like there's details and here that are getting blurred out that I want to bring back in without bringing more noise into my scene so I'm going to increase that detail recovery now I have to be careful like this I've got ahead and increased it too much and the noise has been reintroduced into my scene all right I'm just gonna leave all of that there let me go ahead and decrease the gamma just so you can see what happens when I decrease the gamma and all of a sudden everything has gotten very smooth if I increase the gamma you can see right here these lighter tones have been smooth but not the darker one so I'm gonna leave that there at 1.7 for now I'm gonna finish explaining things and then we'll go back through and actually edit the image so right now the chrominance is automatically being applied but if I want to I can hit manual and then I can go ahead and deal with the chrominance myself so you notice immediately I have a red green channel and a blue yellow channel and then I have a master Channel so if I decrease if I decrease this it will add more noise into the scene whereas if I increase it there should be less noise in regards to color now I've got a lot of green in my scene so I'm gonna reset this to its default value of and then I'm going to increase the chrominance for red and green just so you can see what happens well in that I'm going to decrease this you can see what happens see when I decrease it there's a lot more noise that gets introduced if I increase it it's a little bit harder to see but those greenish areas actually have less noise than areas say like this blue area right here let me increase the blue yellow oh and you can see here there's been specific noise reduction applied to that blue area now for me personally I very rarely come into the chrominance I normally just leave that on the automatic global of course if you want to deal with the chrominance curve you can go ahead and see what happens when you increase the values and of course this curve just works like any other curve in raw therapy we're adding or decreasing points will give you more control now before I talked about the banding that was happening where there was kind of a pattern this median filter would be a way of dealing dealing with that and what that does is it looks at a different looks at a grid of pixels and then uses that to determine what is a shape and what isn't so if I turn on the median filter you can see that I'm actually having quite a bit of noise reduction that's that's gone on and the median currently my median method is looking at my luminance only if I wanted to look at everything I could use the la be method and actually that's working well because there is so much color noise here and then of course the median type I can choose between a 3x3 soft or an hard grid all the way up to a nine by nine so I'm going to choose nine by nine and that has gone ahead and used a nine by nine pixel grid to look in and you apply a noise reduction the problem is I've blurred out quite a bit of my image by doing so but I've also gotten a rid gotten rid of quite a bit of the noise too and then of course the iterations is the amount of times that Roth RP will look at that grid to make sure that it's doing the right thing currently instead two one let's go ahead and increase it to two or three and there's no noticeable difference well there is look at the eye right here currently I'm at one if I increase this to three that I then becomes more blurred so what I want to do is I want to look here at these eyes and I want to actually edit this image so let's go ahead and turn this off and come up here and reset all of this so we can go ahead and edit the image and get rid of as much noise as possible this particular image is so noisy I don't think we can ever get rid of all of the noise so the first thing that I want to do is I want to decrease my gamma and I want to do that because I know that I have noise across my whole image I don't want the noise reduction tool to only look at the light parts and image then I want to increase my luminance and then decrease my detail recovery to zero I'm going to increase and I'm looking for a balance I'm looking for there to still be detail as well as noise reduction so let's keep increasing let's bring it back I think about 40 is probably pretty good now let's increase the detail recovery that's introducing a little more noise into the scene maybe twelve twenty and I do find that my best results are when my detail recovery is about half of my luminance slider I'm going to leave the chrominance on them on automatic and I'm gonna come down here to my median filter and turn that on now this is too much too much blurring that's gone on so let's go ahead and go back to a 3x3 soft grid and the iterations let me put that back to one and increase that what about two so you can see that we have severely reduced the noise let me turn this off so you can see this is what we started with this is what we've ended up with if I want I can actually increase my sharpening to maybe about 400 just to add a little more detail and a local contrast I can maybe increase the radius okay so I hope that this explanation has been helpful if it has let me know in the comments down below thank you guys so much for watching please like comment and subscribe if you so choose and I will see you next time

Channel: jacob swing

Views: 3,972

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Id: kVribo45AsE

Length: 15min 27sec (927 seconds)

Published: Wed Mar 04 2020