Sharpening, Chromatic Aberration & Vignetting in Lightroom®
When I spoke to the engineers initially and actually did interview with them several years after the first version of Lightroom came out, I asked them about the detail panel and sharpening. Because we're in the raw processing stage here, so technically there's a sharpening work flow, quote, unquote, separate from a digital work flow. And the theory behind that is that, some of the Adobe gurus came up with this theory, is that is the raw processing stage, you don't wanna sharpen your raw image that much, because it's not sized to whatever the output is. So sharpening is typically applied depending on how it's going to be shown, how it's going to be sized, enlarged, or reduced. And so if we add too much sharpening at this point, we're actually adding digital artifacting to our image, that may make it look worse if we blow it up or if we shrink it down. Blowing it up would be a bigger issue than shrinking it down typically. So at this point I don't wanna really go crazy on sharpening. I'm...
gonna reset this. If you double click anywhere it resets the sharpening, and it looks like they redid the defaults here, so the number's a little different, it's now at 40 instead of 25. I don't know what that means, that's something in the last update they just did. But what the engineers told me is they've gone in, for cameras that do have anti-aliasing filters, that slightly blur the image, right in front of the censor, and they've figured out how much sharpening needs to be applied to overcome the anti-asling filter, anti-aliasing filter, excuse me, right in front of the censor, and that, even though the default numbers are the same for every camera, the actual amount of sharpening is different. And so if you just don't touch it, you're fine at this point. If I'm gonna go in and add some noise reduction here below it, like say I create, I go in and I zoom in and then I see there's a little noise, but I don't think anybody's gonna really see that in a print. Maybe I'm gonna add a little bit of noise reduction, maybe I'll go in and add like four or five points of sharpening, 'cause noise reduction is technically blurring your image slightly. But other than that, I typically don't add any extra sharpening to any of my images at this point. Once I get them into Photoshop, and maybe I've resized them for a print, or I've resized them to go on the web, I will add sharpening then, that's why there's sharpening in the export module of Lightroom. You can chose how the image is being resized and how much sharpening is being applied to it. So just be aware of that. This is how I do it, some people I know, they add a little sharpening here just to crisp it up. There's also what's called creative sharpening which we can do with the adjustments brush up here, or I can just make Tony a little sharper here, than the rest of the image. So that's a choice you'd make. But, you know, I'm not gonna do that right now, we'll see if I do that later on. So just to explain this, the noise reduction's amazingly powerful. If you hold down the option key here, it shows just the lab colors. So you're seeing not the colors, you're just seeing the grain itself. Same with detail, you can go in here and really, it'll show you exactly what it's affecting if we zoom in, it helps if we're zoomed in. Let me so that again so you can see. It's affecting maybe a little bit more of the grain, a little bit less of the grain. Because of time limitations, I'm going through a little bit of this a bit quickly, but there's all kinds of sub-things that I'm not necessarily pointing out, 'cause we'd be here for the next two days going through everything. So noise reduction here, luminance, noise, is typically grain size, grain structure. Color noise is typically if you have red, green, and blue dots all over the place. If we do this, you start to see these little red, green, blue dots, so I always leave color at the default at a minimum. And if I double click on that it goes back. If I start to see those red, green, blue dots become worse, maybe I'll increase that a little bit. And if you're shooting, I mean, the cameras are so good these days, ISO 60-400 not the end of the world. I actually love grain in images so I'm not too crazy about noise reduction unless it's really seriously affecting the image. Especially if you're shooting with a really high megapixel camera, like the D850, or the Sony a7R III, or the Canon 5DS R. Those are such giant files that when you zoom in on your screen you're probably seeing them bigger than you ever will in a print. And even if you print, when you print something, the ink spreads and it kind of hides the noise. So even if it may look egregious on your screen, you may or may not be able to see that noise in a print. Or on Instagram definitely not, because you're gonna downsize the image so radically that noise is gonna vaporize. So, you know, people get kind of crazy about reducing noise, you'd have to do some testing on your own to figure out where that fine line is, how mch to remove or not remove. But for me it was my D850, for example if I'm not shooting, maybe if I'm above ISO I'll actually remove some noise in Lightroom. Anything below that, like ISO I can't even tell the difference between 800 and 400 on my camera. So it's like (scoffs) who cares, just leave it as it is. That's my taste though, so it's up to you. Down here in Lens Corrections, they very conveniently gave us the Remove Chromatic Aberration box, which let's even see if we have any in this picture. Chromatic aberration is where different wavelengths of light are focused to different parts of the censor, when they go through the lens. 'Cause any time you have a wave going through a medium, the light is bent. Just like the light waves when you're in a pool, and then you see the light all over, it doesn't look the same in the water as it does in the air. So if you have red, green, they might go to different places, you might get a little purple fringe, a little red fringe, a little green fringe. Adobe, very conveniently, instead of having sliders, they just gave us these check boxes which look at the image and take it out. There's maybe a hair right there, there's a little bit going on, that's not much to speak of. Typically you see more chromatic aberration in wide angle lenses, but it can happen on any lens. I have 600 f/4, 600mm f/4 lens you can see chromatic aberration. Even though that's a $12,000 lens that's incredibly well corrected, it just, it's the laws of physics. I can make my glasses show me chromatic aberration just by looking out of the corner of my frame. You see it in movies all the time because it's extremely difficult to remove from video. Like, if you watch movies and look for color fringing, you're gonna see it a lot. If you haven't been looking for it sorry if I just ruined a bunch of movies for you. Go ahead Tony.
From the check box on chromatic aberration, is there... If you don't check that box, do you get a superior image? Or another way of saying it is, by checking it, does it degrade the image in other ways, other than taking out the chromatic aberration? Otherwise why not just have it on there constant?
That's a good point, and I would. You can actually create developed presets so that when you import images, that box is always checked. And that's not a bad idea. It does not necessarily degrade the image, I mean, you might actually know more about this than I do, Jim. 'Cause you're Mr. Photoshop expert.
Sort of, sort of. I don't think it does. But I would kind of leave it to the expert.
I mean, you can take it to extremes when you go over here to manual. 'Cause there's two different things going on, there's color fringing and chromatic aberration, which are technically two different things. Color fringing is light bending around objects, especially where there's a really high contrast edge, like something's backlit. And because it's sliders here, you can go way too far and create all kinds of weird edge effects that you start to see. Let me just see if we can even make them happen. And it starts getting really funky, I don't really see it happening. Wow, that's pretty amazing it's not happening on this image. So, there's no color fringing happening on this image, 'cause the light was coming from the side. So you can go too far with this de-fringe part, because sometimes it might be chromatic aberration, sometimes it might be a combination of chromatic aberration and color fringing. And that's where you use this de-fringe tool. And honestly this is something that drove me crazy for years, especially in print world, most photographers never go to this, even pros. I've seen lots of pro's images where there was massive chromatic aberration and they did not take it out, and when that image got printed in a magazine or wherever, when you sharpen chromatic aberration it's just like a neon sign that they didn't finish the processing all the way, and they've got giant purple fringing around their horizon. And that's kind of like, dang, you should've taken that out. So, you know, I always for every image, and this is why I'm talking about slow, there's the old adage, you can have quality, you can have it fast, or you can have to cheap, pick any two. You know? Here we are. If you want it fast, well I might miss the color fringing, I might miss this, I might not get the image all the way. And I'm explaining it to you so it's taking exponentially longer here. You know, you've gotta really go in and zoom in, I always click the profile corrections, but often I'll actually take out the correction for my lens. So what Adobe's done is they've gone in and figured out how certain lenses, the aberrations of the lens, and they have lens correction, quote, unquote, to do this. My Hasselblad has lens corrections, you know, for every lens. And the 100mm lens, a half of that Hasselblad is one of the sharpest lenses in the Hasselblad line up. It has serious chromatic aberration. So chromatic aberration's not necessarily a bad thing. If you're seeing a lots of chromatic aberration that's probably because that is a crazy sharp lens. The sharper the lens, the more chromatic aberration you can get. If it's a really soft lens your probably not gonna ever see chromatic aberration out of that lens so that's telling you something. So that lens can be tough when I shoot protraits with it because there might be massive chromatic aberration I have to really go in and work on. But holy mackerel, it's unbelievably sharp. So just a little side note there. In Vignetting, you know, this is taking out the vignetting that the camera lens is naturally producing. And sometimes I leave it in, sometimes I take it out, sometimes I leave this somewhere in between. You know, I kind of like those corners a little darker. It's up to you. Sometimes I take it completely out, and I go down here to Post Crop Vignetting and I add my own custom vignette back into the image. Which I'll probably do for this one. Transform here, is to align your image, since this is not an architecture image I'm not going to use that for this guy. I don't use it that often since I don't shoot architecture very often. Let's just say the vignetting here, and post crop vignetting, what the mean by that is if I crop this image, the vignetting is gonna respect the crop, however it was cropped. So you wanna make sure you've got the image the way it is before you start drawing the vignette, because it would change if you cropped the image, and it may not be the way you want it. So I typically darken it all the way just so I can see what's happening. I find my midpoint, kind of where I want it, and then Roundness here, you can see how round or square it is, I kind of leave it somewhere in the middle there. And then Feather, I like to feather it a lot, because I'm gonna back this off to the point that you would never know I added a vignette. So it might be a little bit more than the camera saw, somewhere in there. You know, that's negative six, so that's a very slight vignette. But if you didn't see me draw that, you would never know that I put that in there. So, lightly on the vignetting here. What I'm thinking about in Calibration down here, if you're shooting in a studio, like Jeff here in the audience. And you're shooting similar lighting, similar scenes, you could actually do calibrations specifically for your cameras, to tune the color for your camera if you wanted to. If you're shooting outdoors and in different places every day, I would not recommend doing any of this. So that's why I have that closed down there.