The "Fill Opacity Eight"

Now the primary purpose of the Fill value is exactly what I showed you in the previous exercise that is it allows you to modify the opacity of the layer itself independently of layer effects and other specialized layer functions. However, out of the 27 common blend modes, eight of them are affected differently by the Fill value than they are by the Opacity value and frankly, between you and me, they are better affected by fill and I call these the Fill Opacity Eight. Now I haven't demonstrated how these modes work yet, however, when we get to our specific blend mode discussions in subsequent chapters, it will be important that you're familiar with this information.

So, the Fill Opacity Eight include inside the Darken group, both Color Burn and Linear Burn. Inside the Lighten group, we have Color Dodge and Linear Dodge (Add) that's actually the name of the blend mode. In the Contrast group, we've got three of them; we've got Vivid Light, Linear Light and Hard Mix and then finally, in the Inversion group, we have the Difference mode. So just so that you have a sense of what's going on here, I'll demonstrate a few of these modes. I am working inside a document called Fill Opacity Eight.psd found inside the 01_intro folder.

I am going to go ahead and turn off the top three layers. Notice that that the Assyrian layer is selected inside the Layers panel. Then I'll go up to the Image menu and create a copy of the image by choosing the Duplicate command and I'll call this duplicated image Standard Opacity and click OK. All right! Now I want to display the two images side-by-side. So with this new image selected, I'll go up to the Arrange Documents icon, up here in the Applications bar, click on it and choose the vertical 2 Up option. And because the Standard Opacity window was active, it now appears on the left-hand side. All right! I'll now press Shift along with the Spacebar so I can scroll both of the images at the same time like so.

Now the most obvious of the Fill Opacity blend modes, is Hard Mix. So again with that Assyrian layer selected, I'll go up to the Blend Mode pop-up menu and change it from Normal to Hard Mix and we end up getting this just absolutely hideous effect here. We are just left with eight colors, nothing more, by which I mean black, white, we also have red, green and blue as well as cyan, magenta, and yellow. Every single pixel is one of those eight colors and that's all we have left. So we've got this terrific degree of posterization.

You might figure well, maybe we can tone the effect down a little bit by reducing the Opacity value. So I'll press the 5 key to reduce the Opacity to 50% and we end up getting a 50/50 mix of the effect we saw just a moment ago along with the background image which, by the way, looks like that. So the result is a pretty poor effect in my opinion. Let's compare that to the exact same blend mode set to a Fill Opacity value. So I'll go ahead and click into right- hand image, change the Blend Mode from Normal to Hard Mix once again and then this time, I'll press Shift+5 to reduce the Fill Opacity to 50% and we get an entirely different effect with much smoother, more organic transitions. All right! Let's take a look at a few others.

I am going to click in the left hand image once again, change the Blend Mode from Hard Mix to Color Burn, which is one of the Darken modes. We end up getting this dim grim effect on left. Click in the right-hand image, change it this time to the Color Burn mode as well and thanks to the fact that it's the Fill value that's set to 50% as opposed to the Opacity value, we end up getting what is still a very dim effect, but a better result. All right! Now I'll click in the left-hand image. Let's see Color Burn's opposite which is the middle mode in the Lighten group, Color Dodge, and then I'll click in that right-hand image and change it from Color Burn to Color Dodge as well.

Now this time, the two effects are little more similar than what we've seen in the past, but notice over here on the left-hand side, we have a series of posterization, that is the sort of flat light grays that are going on here, in the cheek and along the nose, whereas that same region over here in the right-hand image provides us with a lot more detail. Just one more effect, I am going to click in the left-hand image once again. Let's change the Blend Mode this time to the first of the Inversion modes, which is Difference and notice that we do indeed invert certain details of the image particularly, those portions of the image that lie in the shadow region of the carving.

Compare that to, if I go ahead and click in right-hand image and change its Blend Mode from Color Dodge to Difference, this time we get what appears to be an entirely different blend mode and yet, the only difference because we're still working with the Difference mode is that the Fill Opacity as opposed to the Opacity value is set to 50%. So hopefully, that gives you a sense of what's going on. I don't expect you to remember which modes are part of the Fill Opacity Eight and which aren't. However, I do want you to know that if you end up applying a blend mode and you get too heightened of an effect, it's entirely possible that you can rein it back more successfully using Fill as opposed to Opacity here inside the Layers panel.