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Lesson Info

Correcting for Noise

Today we're going teo actually start in camera you know why? Because whenever I teach a class like this, we do camera out the very beginning and then it seems like we never use it again afterwards and people think of it as like a separate thing all the things we talk about throughout all the days there's usually component within camera up, so I want to cover some of the things that we didn't have time to cover during the other ones because they're very important in them will also look at some of the creative techniques we can use some of the retouching, that type of stuff that we're planning on doing today, the other things we're going to cover, their retouching, creative effects and finishing techniques just stuff we have to do if we're going to send our files off to other people because not everything's obvious like, should I sharpen my image? When should I sharpen my image? How much anything to worry about when I do that, that kind of stuff. So anyway, we got a lot to cover starting...

off camera do retouching creator of facts and finishing techniques let's jump in gets going so in camera do you remember when we had a series of images with horses? Very first images we worked with some of those images we first looked at him were really dark and then afterwards we process some images that were from iceland that were really dark as well, and we brighten them up. One thing I mentioned was the noise is hiding in the dark portion of your image, and any time you brighten up the dark part of the image to make it easy to see what was in there and it used to be so dark, you couldn't see it. Part of the detail that you're getting is the noise that was in there, so we need to think about how to deal with that. So in this case, what I'm going to do is zoom into one hundred percent view. I don't know if you remember a nap with a very quick way of doing that, and what it is is you double click on the zoom tool and the upper left of my screen that'll get me one hundred percent view, and then I can use the hand tool to move around. And when I do that, I can see a very noisy looking image. So actually, you look at her leg, it looks like it's he's got some, I don't know either mega hairy legs or something, but it's noise uh, in there, so to deal with that, we have a bunch of tabs over here. In camera, we've only dealt with maybe two of those tabs let's take a look at a few of the others this one right here is known as the detail tab and in the detail tab we have things related to sharpening and noise reduction in sharpening is actually very important when it comes to noise because with default settings, if you look at it here, the defaults it is sharpening your picture because if your picture came from a digital camera, it usually is just slightly soft when it comes in, and part of the reason for that is the majority of digital cameras out there have actually a filter in front of the sensor that's somewhat softens the image you might think that would be a bad thing. Why would you possibly do that? But if you don't because of the way the sensor is built, if you had fabrics and other things that have patterns in them like the weave of fabric, you can get a more a pattern if you're not familiar with moray pattern, have you ever seen it where you take two screens like you'd have in a screen door and you rotate them slightly? You get this weird pattern going up that's amore a pattern and you get some of that stuff happening in we weave of fabric and other things if you don't have that filter in front but it makes your image slightly soft, and so here we're just trying to compensate for the slightly soft image our camera gives us, and this is the default setting. Well, the problem with it is there is a slider down here at the bottom called masking in that slider, if we bring it up would cause this to not sharpen the entire picture, but on lee, sharpen it. Where there's more obvious detail, and not where there's subtle detail well, the default setting for that zero what that means is don't limit where this image is sharpened at all, and so that means if we have an area like over here where there is no what I would call you awful detail meaning can you see hairs on her leg? Can you see? You know anything when it comes to the detail of her leg right there shuriken see where she's wearing jewelry down here, but not up in this area here, and so if this is not useful detail instead, it's noise it doesn't make sense to me to sharpen it, because sharpening is going to exaggerate it, make it easier to see, make it jump off the image more so what I want to do first is to make sure that the sharpening is on ly applying where there's really useful detail, where there's stuff, where whatever's in there the detail that's there is something I actually want you to pay attention to so I'm going to zoom out on this picture I'll double click on my hand tool to get one hundred percent view and I'm going to adjust the masking setting now the problem is when you bring up masking its really hard to tell when it stops sharpening the really noisy areas in on ly concentrates on the useful detail but there is a hidden feature in here that can show us exactly where it will sharpen our image and where it won't what that is is the masking slider when I click on it I'm gonna hold down the option key that's the whole key in windows if I don't hold it down when I bring it up it's really hard to tell what it's doing but if I hold down the option key and keep it held down then when I click it changed my view of the picture right now it's showing me a mask like a layer mask it's just a mask within camera and remember with masks if the mask is white it means let this layer show up it was a layer mask well this means let the sharpening show up and if I bring this slider up you see how black starts being introduced in a mask and you remember how in a layer mask if you paint with black it hides whatever's in that layer well, in this case, it's hiding the sharpening it means it's not going to sharpen those areas that are turning black as they bring this higher and higher and higher you see more and more the image turning black well, those black areas of the parts that won't be sharpened. So what I want to do is just glance at the picture and try to remember overall, where there is areas that don't contain useful detail. We're useful is not the right word. I just my brain doesn't isn't attached to the right word right now just detail that is important or detail that you would want to actually emphasize. So, for instance, up here in the sky, that little corner of the sky there's nothing in there that is truly detailed, that I would care if it was prominent or not right here the edge of those clouds that's useful detail, that's something where yeah, I want you to be able to tell what the edge of the clouds were there, that kind of stuff, but in between these clouds not really detailed if I look at the horse itself there's not much detail in the dark portion of the horse it's, where the edges of the hair are that this detailed is where this white area on the front touches the darker area that's detail s so what I'm going to do is just try to remember where there wasn't much useful detail and I'm going to bring up the masking until those areas turned black so up in the sky getting those areas now to turn black and you see it on the body of the horse he's kind of almost random white squiggles in it I'm gonna bring it up until those random white squiggles start to turn black let's say there but if you look at it do you notice that the edge of the mane of the horse still has the white stuff on it meaning it will still be sharpened and you notice that part of the front of the horse's head where it had a lighter color to it that has white stuff on it it will still be sharpened but the horse itself now will largely not get sharpened and if I want to push it further if you look at her leg it still has some white on her leg I could keep going and see if I can get it toe largely get off of her leg about like there maybe I'm starting to get it words mainly off the leg it's still those has some on the main of of the horse where troops down like by his eye that kind of thing in things but anyway by doing this getting up this high now we're not sharpening the noise so I'm not going to do that in every single image necessarily it's the images where I had an image that was overly dark and I brightened it up and in doing so, noise became prominent became easy to see and I hate the noise. Well, then we don't want to exaggerate the noise by sharpening it, so we need to do something to get the sharpening out of there and masking is what's going to do that, then? Below that, we have areas for noise reduction, so first we make sure we're not exaggerating the noise with are sharpening, and second we try to reduce or eliminate the noise so let's double click on the zoom tool again to get up to hundred percent view and let's move around and let's see if we can reduce our noise so we have two kinds of noise reduction. One is fluminense noise reduction fluminense is just a fancy word for brightness, and then we have color and there's two different kinds of noise we can have with default settings. You'll find that the color setting has turned up because most cameras produce a lot of color noise, and if you bring it down, you'd see it can you see that it looks like what I call christmas lights it's random would colored kind of specs we'll most cameras blair earn a good amount of that and so the default setting if I double click on the slider called color, if you remember now, but in camera double clicking on any slider will reset it to its default. But it's usually high enough to largely eliminate most of that. But if you had some extreme noise, the color noise you might need to adjust this. So if I bring it down too far, I see what I call christmas tree lights and bring it up. Bring it up if you bring it up too far, then what can happen is where you have true detail in your image. Let's say you have somebody with a shirt on that's multi colored in their small little blobs of color within their shirt. It won't know the difference between that and noise, and it will start blending into the surrounding colors so we don't want to just crank this up. You know, if we have, uh, detail in our picture that involves changes in color like somebody's busy shirt they might be wearing so I could bring this up and get it. Tell that little specks of color start to blend in with their surroundings. What's wrong one color, then there's another. Slaughter, because sometimes even doing that which is designed for getting rid of kind of little specks of color isn't enough, because you'll have kind of patching this to the color. Can you see if you can easily see this on the broadcast because of the compression that supplied but right here is like a yellowish blob to me like a bigger one. There's a kind of magenta is hint right here, there's just kind of blobby in the look of the color when I looked out of my screen. Not sure if you guys conceit on the broadcast or on other things because it's very subtle. But if you see it on your pictures when you're adjusting things and it's, not little specks, which is what the color noise looks like. It's blobs like the size of your thumb showing up, then there's a choice here called color smoothness. And if you increase it, it will usually smooth those out. You see if I could bring it down and it might emphasize it. But I could more easily see a yellow blob here. Magenta blob there greenish blob here in bringing up color smoothness works mohr with those larger, I'll call them blob jewel's, uh so we can try to reduce or eliminate it, but again, be careful if you bring this up to high, you're going to find the general color detail in your picture. The important true detail has nothing to do with noise might start to look more greyish words blending in with the surroundings, so be careful, then we have that's color noise, we can talk about luminant noise, which is just brightness noise that means specs that vary in brightness instead of color, and with that, I could bring this up and start to reduce or eliminate it, but there are two other sliders related to it that air interacting with this slider there's one here called luminant detail and if you haven't overly noisy image, not an average image, but one where you started off with something really dark and you made an extreme adjustment to brighten it and that's, usually when you get extreme noise showing up what I would do when I'm adjusting, this is before I even mess with the slider called ruminants. Take this slider called fluminense detail turn it down to zero that just turns that setting off so it's not affecting the image. We'll talk about what the setting does in a moment, but with that turned up, you're not getting the full effect of the top slider. You have something in there that is not showing you the full effect, so now I can move this around to see what is actually the highest setting I would want to use for this image. This is with none. I see quite a bit of noise, and then I bring it up and I gotta decide I'm going to try to completely eliminate it, because if I d'oh oftentimes you get a really soft looking image it's a matter of good balance between the image not becoming too soft in the image, not having too much noise, you gotta find a good in between. So I'm gonna come in here and see, I think right about and there I'm starting to get to a point where I'm not minding the noise as much it's, not something that's bothering me, but in doing so, there's nothing right now, trying to prevent the same thing happening to the real detail in the picture. So the real detailed the picture will start looking soft at this point and that's, where the slaughter called luminous detail comes in when it's turned all the way down it's not trying to differentiate detail from noise it's thinking they're both the same, we're just softening our picture. Now, when I bring the luminous detail up it's trying to make that noise reduction on ly happen, where thinks there's noise and the way I would deal with that in extreme cases like I'm talking about here is I would crank it aside as it goes, and then I'd slowly bring it down find the highest setting that makes the image look realistic because what'll happen is you're going to get weird, artificial looking kind of swirls in your image where the noise used to be because it's acting this there's detail there and tryingto retain it and you want to bring it up in town, you find the highest setting that doesn't give you weird looking stuff like your noise reduction still kicking him where the noises and somewhere down in there because now before I know it's very hard to see in the feed because any time you have noise it compresses the feed in order to send it out in and doing so things like noise and really fine details really hard to discern s I'm not sure how useful this is for you to look at it, but in general, if you ever have extreme amount of noise, the way I would suggest you dealing with it is take this thing called ruminants detail turn all the way down just to turn off, then adjust your luminant ce in tell you reduce the amount of noise to a level that you think that's, what you want to go for and then to try to get as much true detail back in your image, crank the luminous detail all the way up and slowly bring it down until things look natural because if when it's cranked all the way up, the areas that were overly noisy usually will have weird swirly little stuff almost like look like yet took a pen and started doodling in there and you want to bring it down until this area's look natural, there is something called luminous contrast you'll find that on the vast majority of images that you have, it won't seem to do anything but on some images you will find that it will bring some contrast back into the dark portions of your image so that if I come over here and look maybe at the horse's head things if I adjust so they don't need to zoom up so far the luminous contrast you will see some additional contrast coming into those dark areas. It will be rather subtle, though, and that can be a way to to emphasize the detail that's there but you're going to find on a huge number of images it won't seem to do anything so when it comes to noise, first thing we think about is sharpening don't exaggerate it unnecessarily so there was a slider called masking and I bring it up. I use that masking slider on a huge number of images just so you know, even if they don't have huge noise problems. Let's say you have a, uh a landscape shot that includes a blue sky and in the blue sky there were no clouds whatsoever. There's no birds there's just blue sky. How much quote unquote useful detail is there on your blue sky? Is there any texture in it? Is there not typically? There shouldn't be right so that if you're going to sharpen it in the default setting, sharpens everything. Well, anything that's in that sky is going to get exaggerated. That means any noise that your camera happens to be putting in there. If you have censored dust specks that are in there, they're going to be emphasized and all that. So why not? Anytime you have a huge respect expanse of blue sky, why not take that masking slider under sharpening? Bring it up a little bit till the sky turns black in that preview, hold on option bringing up sky turns black you know you're not exaggerating that area that has no useful detail, so the sharpening can't really be useful there.