Join Taz Tally for an in-depth discussion in this video Evaluating tone: Focusing on highlights, part of Advanced Photoshop Color Correction.
In this video, I'd like to discuss how to analyze an image in terms of what its color balance is. And in particular, in this video I want to talk about highlights, evaluating and measuring highlights. So let's start with this image here. We're going to do two images during this movie. And here's a image with people in it, and outside of a building. It's a fairly common type of image that's taken and first thing I do is a visual evaluation of this image. So, I look here and I say, alright.
As we know from previous discussions, we try to look for neutrals or important portions of the image. And, obviously here we've got some neutrals. Some, maybe some white highlights. Some diffused white highlights. Perhaps up here in the sign or down here in the snow. This may or may not be here. We clearly have some shadow area down here in the clothing that could be a detail shadow area, and then we've got skin tones. Alright, we're going to focus on highlights here. So, I'm looking at the image and going, alright, well, this is probably a, a light highlight area, and then when I look back in here, I see, oh, there may also be a specular highlight.
And, as you probably already know there's two kinds of highlights. There's a diffuse highlight, which is the lightest portion of the image that has detail. Then there's a specular highlight, which is blown-out pure white not supposed to have any detail. So, I'm always on the lookout for specular highlights, not because I want to measure them but because I want to ignore them. So, this is a specular highlight which is a reflection and notice that if we zoom in on this, we can very clearly and easily see. It is indeed a specular highlight because it's a reflection of the glass.
Okay. So, that's what I'm going to be paying attention to conceptually, right is the lighter portions of the image and anything that is supposed to be white. Now, let's move over to the histogram to kind of continue our analysis. First thing I look at is just the overall distribution of tonal data in the image. And notice, this has pretty good distribution data. All the way from the highlight, all the way down here to the shadow. But I also noticed that, oh there's some big spikes here on the very highlight end and in Photoshop there's this little warning that says, whoa, watch out, we're losing detail here.
We're overexposed. Which shouldn't be a surprised, right? Because, predicted because the specular highlights. Well, I'm thinking that this is likely the specular highlight right over here. Alright, there maybe something else but it's particularly that and then down here, notice that most of the data stops here but there's some blue that goes all the way to the shadow end. So we've got detail all the way to the shadow and let's just take a quick look at the individual histograms that go. Yep, there's the spikes and particularly on the red. Notice how tall the red is. That's curious.
But, when if you look carefully, it's a little subtle here, is notice that the blue histogram is offset a little bit to the right of the, particularly the green, but also looks like perhaps the red. Pretty high spike in the blue. Something, hm, maybe there's a blue cast in this image. When I look quickly over on the shadow end, we'll come back and look at this in more detail later, that's where I see all that blue data down here. So, I'm thinking, hm, there's a lot of blue in here, above the highlight and the shadow end, that's a hint that there may be a blue cast in here. Okay, so what we want to do next now that we're getting a sense for this image, there's a specular highlight, there's some white diffuse highlights here and maybe the sign.
Looks like we've got a blue cast in the image. Let's go ahead and now move to a little bit more quantitative analysis of the image. I'm going to move my histogram over here and I'm going to move up into my background. Our next step, then, is to come underneath here and we're going to go ahead and make our Curves Adjustment layer. And remember, this is the tool of choice because it's so powerful. It gives us control of all the tonal values on all the channels and including the master channel all across the image, and it's non-destructive. Alright so, I want to use this to help us identify, you know, where the specular is, but particularly where the diffuse highlight is.
Alright, and we can do this by coming underneath here and choosing Show Clipping for Black and White Points. Alright, and what that does when you turn that on, if you click on the White highlight here, it shows you if anything is blown out on the image. And notice, whoa, there's the specular right up here, we can see the blown out specular. And, we also see where the red is in the image. There's a lot of red in this yellow jacket, alright? And that's that big spike that we saw in the red histogram over here. That's not a diffuse white highlight we're looking at, but now we see where that red spike comes from.
And, it just appears to us, this image is just a little bit over exposed. Because of the overall peaks but also that peak in, in the yellow jacket. Alright, so we're going to click here. By the way, you don't have to turn this on here, the show clipping. You can just hold down your Option key, Alt in Windows and click and you'll get the same effect. That is, you can see where the specular diffuse highlights, things that are blowing out. And notice in this image that when we Opt+click or set the menu and I just move this a little bit to the left, do you see how this white foreground really lights up over here? And we can see that this area is, it's just a little bit lighter than the specular highlight, so I'm thinking, mm, we may end up with some blown out highlights here as well.
Let's just zoom in using those keyboard shortcuts we talked a little bit earlier in the course. And let's just see where the, right in here. I'm going to hold down my Shift key, right. I'm in the Eyedropper tool. And then, when you hold down the Shift key, it creates that Color Sampler Point tool. And then I just click. Alright, then I can reconfirm, yep, that, that's the area that I want right in there. Alright, so I set my color sampler point. By the way, always remember to return that highlight or the shadow, whichever one you're working with, to its starting point after you set the color sampler point.
Then we come over here and then we look at our RGB values. And we see, sure enough, alright. This is supposed to be a diffuse white highlight. Alright, but it's not. It's almost all the way to 255 and notice all the values are completely the same, 254, 254, 254. Alright, so, we're going to set that to help us set the lightest portion of the diffuse highlight, but in circumstances like this. You know, I'm also going to set another diffuse highlight, some place that it's not particularly blown out, but it's still on the white snow.
So, I'm going to move this over the image and while I'm moving this over the image, I'm going to be watching the RGB values that I see here, alright? Until I start to see values that have a variation in the red, green and blue so that they're not all equal. So, I'm going to set a color sampler point, probably right about here. Shift, color sampler point number two. The reason why I'm going to do this is, that's the color sample point I'm actually going to use to do my color correction. Because this one is really not a lot of help to us. Because all we can see is 254, 254, 254.
Later on we'll go ahead and adjust both of these points. But for now, that's what we're going to set our diffuse white highlight, is in color sample point number two. Alright, so. We have evaluated the highlights, we know we've got a little bit of a blue color cast and we look at color sample number two, we see 245, 249, 253. Sure enough, we've got that blue cast alright. And no matter where we put our Eyedropper tool, we can see that the blue is always high. So, that confirms our suspicion that we had a blue cast in the image.
So, that's for that image. Let's just take a look at another image, that's a little bit different. And we'll be correcting both of these images as we go along. This is a image that I shot of the Harding Ice Field, here in Alaska. And, when we look at this image we go, oh wow lots of highlights in this one, right? Lots of really bright areas also some shadow areas, more on that later. And I'm looking at this, I'm looking at the distribution of data and I come over here and I'm going, okay I want evaluate and find the lightest diffused highlight. And this is a really critical image because with an image like this that has so many highlights, it would be easy to over expose this image.
So, I look at my histogram and I see the distribution of data, you know, unlike the last image, you know I don't see any big spikes in the highlight end or the shadow for that matter. That's a good thing. That the other thing that I see here is unlike the last blue cast, which was kind of subtle, this one is pretty dramatic. See how offset the blue is right here then green and red? Offset blue from green from red? So, I'm pretty confident we've got a blue cast here in this image. So, good tonal distribution, no spikes on either end, but we do have a blue cast.
So, what do we going to do? Let's go ahead to Curves and let's go ahead and Option or Alt and click here. And let's find the lightest portion of this image. And notice how the blue comes up first? Confirming the blue cast, alright. And then we find the area that starts to blow out first, which is going to be right up in here. And I'm going to zoom in on that area right there and just confirm. That that's where it is and then Shift+click to place this point and then come back, and let's evaluate 229, 238, 249.
Sure enough, alright. So that's where the lightest diffuse white highlight is and we can see that it's not blown out. But, it does have a pretty strong color cast to it, 229, 238, 249. Now, we could stop there and just do the correction based upon that, but you know with images like this, that there's so much of it. I were, we're shooting ice and snow. You know what I like to do? I like to place a couple more highlight. Not necessarily the diffuse highlight but a couple of more highlight points. I'm going to place one Shift and click here, in the well-lit area.
And also one up here, maybe somewhere in the shadow area, alright. So, I've got the color sample points two and three, which are not super diffuse highlights but they're in a neutral area. Since there's so much of this in here. I do this on a wedding dresses and things where there's lots and lots of white. I'll place than one color sampler point. So, we've got, down to, into the quarter tone and down towards a midtone, where we can take a look at those values as we do our corrections later on. So, there is two analysis of two different kinds of images we were looking at the highlights. We've got a specular highlights and diffuse highlights.
We've placed a couple of different color sampler points in critical areas of both images to help us not only evaluate but adjust our images later on.
- Using color workflow tools: Bridge, Photoshop, and Camera Raw
- Setting color workflow settings
- Setting up a monitor and viewing options
- Assigning a workspace and color keyboard shortcuts
- Understanding grayscale values and color
- Working nondestructively
- Working with neutrals
- Using targets for color correction
- Evaluating tone and color
- Evaluating and correcting skin tones
- Working with color sampler points and Curves efficiently
- Adjusting tone and color
- Performing target-based corrections
- Sharpening a color-corrected image in Photoshop