Blending Modes: NormalBy Nikolai Sklobovsky.
This mode is the first, default, and, as its name implies, is by far the most commonly used blending mode of all twenty two of them.
Lets see how it works.
First of all, as with all blending modes, you need to have at least two different layers (otherwise there is nothing to blend with). There are numerous ways to get those. You can start with a blank document, paint something, then add a new layer (a new layer is always created in Normal mode) and paint something else.
Lets create a new blank 800 x 600 document with a white background. Just in case I also stroked its borders with 4 pixel black stroke:
1. Select|All (Ctrl/Cmd + A)
This gives our future document a solid foundation, so now we can start to work on our layers.
Lets create a new layer. You can do it by:
- selecting Layer|New|Layer menu command,
- pressing Ctrl/Cmd + Shift + N,
- or, my personal favorite, by clicking the New Layer icon on the bottom of the Layers palette.
The reason I like it the most is the lack of the confirmation dialog. This button simply creates a new transparent layer and lets me go with my own business.
Using Elliptical Marquee tool (M) with the Shift pressed, we can create a circular selection and then use the Paint Bucket tool (G) to fill it with the color of your choice, pure Green in my case.
Even in this extremely simple example we already can see some advantages of our simple Normal blending mode the circle is painted on the second layer, but since the rest of the layer is transparent, we have an image of both the circle and the framed white rectangle on the background.
But wait, there is more.
Now lets click the Opacity word in the Layers palette and change the value by either typing 50 or tweaking it with the mouse. The picture will change to something like this.
The top-most layer becomes semi-transparent and provides a nice see-through effect .
MaskingOpacity slider allows us to change the whole layers transparency level. But what if we want more control over it? Layer Mask to the rescue! Lets perform the Layer|Layer Mask|Reveal All menu command, or simply click on the Add Layer Mask icon located at the bottom of the layer palette. Nothings changed, except for the Layers palette structure yet... Note: there is a separate excellent tutorial on Masking availalble here.
Lets change the situation by selecting a large hard black brush and clicking our picture once somewhere around the center. Our Layers palette and our picture will reflect the change.
The black circle of the mask now allows us to see completely through this black hole. The layer as a whole is only 50% opaque, but our mask commands its center part to be totally transparent.
Another great thing about masks is that our original blue square is, in fact, still whole and has no holes in it. Its easy to see by disabling the mask (by Shift+clicking on the mask icon). The mask icon will get red-crossed and our blue square becomes whole again. To enable the mask back simply click on its icon again. Im sure all our "hard-core" Photoshop actions would not cause any wows thus far, but the important thing is to understand what we did and what we have reached: we learned how to create several layers, change their general opacity and even added a layer mask to control the layers opacity on a pixel-by-pixel level.
Now lets get some more fun with the actual photos.
Lets open two different images we would like to blend. It will be better if they both are in the same orientation (either portrait or landscape) and in the same resolution (unlike one being from a cell phone and another from a medium format digital back at 44 mega pixels).
I picked up an image of a local californian tree with the red leaves and a shot of a swimming pool.
There many ways to add one image to another as a layer.
The simplest way I can think of (for a novice, at least) is probably to do the following:
1. Activate one image by clicking on its title bar
2. Perform Select|All command (Ctrl/Cmd + A)
3. Perform Edit|Copy command (Ctrl/Cmd + C)
4. Activate another image by clicking on its title bar
5. perform Edit|Paste commad (Ctrl/Cmd + V)
You will end up with first window holding two layers now, only the second one being visible.
As you can see, the window you have just pasted/dropped to the second image now contains two layers! Yay, were getting somewhere!
OK, lets close the second window. We dont need it anymore, since all the info we need has been already secured in our new second layer, named Layer 1.
At this point I also like to maximize the first window by double-clicking its title bar and maximize the image inside it by performing View|Fit on Screen command or pressing Ctrl/Cmd + 0 (0 as in zero).
In any case, we have got two layers, made of two completely different images, lying on top of each other, and, naturally, the upper one completely blocking the lower one. Its like stacking two sheets of paper on top of each other: you can only see the top one.
So, whats the point of that?
Sure, Normal mode all by itself does not make much sense in this case. We need to add some layers transparency into the game to see any benefits.
As we did earlier in our circle-square example, click on the word opacity and type 30 (or set its value by dragging your mouse, or any other way). You will see something like this.
With a certain amount of imagination, this new image may be interpreted as a life-like reflection of a tree in a pool. Not bad for a few clicks! You can spend a few more seconds to play with the opacity level to get different effects.
Important thing to understand is that at 100% you will see the upper layer only, at 0% you will see only the lower one. Any intermediate value will get you some sort of a blended image, hence the name blending modes.
More often than not, the Normal mode is used in a combination with the opacity level set to a lesser than 100% and higher than 0% value. The notable exceptions are spare copies of some layer (Background to be one), created and left in the Normal mode to preserve the original layer against any potential damage done by the subsequent modification. All the changes are done to the copy, so if something goes wrong the layer is simply deleted, or made hidden, or its opacity is set to a very low value.
You will notice that the Layer palette would change its view and begins to look like this.
What is represented by this new white rectangle is a layer mask, an object that control pixel-by-pixel opacity of this layer. White color of the mask pixel means the corresponding pixel from this layer will be visible. Black color means the pixel from the underlying layer will show. Any value in between youll get a blend of the two.
Lets do something interesting. Lets copy the blue channel of the tree layer into our new mask and see what it does. As always in Photoshop, there are several ways to accomplish this, I choose the following:
1. Hide the upper (masked) layer by clicking the eye icon on its left.
2. Select the Background layer by clicking on its icon once.
3. Press Ctrl/Cmd + 3 to view the Blue channel
4. Press Ctrl/Cmd + A to select it all
5. Press Ctrl/Cmd + C to copy the selection into the Clipboard
6. Reveal the upper layer by clicking on the eye icon again
7. Alt/Option+Click on the mask icon to bring the mask itself to the editor window you will see a simple white screen
8. Press Ctrl/Cmd + V to paste the Clipboard content into the mask you should see exactly the same picture as you saw in the Blue channel on the step #3
9. Now, the moment of truth: click on the upper channel icon itself to see the result of our actions.
You should see something like this.
At its easy to see, the tree itself provided us with a perfect mask data. Being mostly black from the blue channel perspective, the bark and the leaves created a natural foundation for our mask, effectively replacing the sky pixels from the background layer with the pixels taken from the pool shot.
The sky meets the groundYou dont always have to go through the channel copying. A lot of times the mask can be constructed in a much easier way. Lets consider a classic trick that can often replace a need for an HDR image Heres one of the typical original unedited raw shots where the sky and the ground provide two incompatible targets. The image looks totally flat and uninteresting. The two parts of the image require two different exposures and two totally different post processing methods for each to look nice, yet both are the parts of the same image. What do we do? Well, if you shoot JPEG, you better take two different shots, targeted carefully for each part of the future image and pray to Aperturia, the Muse of Photography that your settings were dialed in correctly. However, if you, like me, are shooting RAW its a childs play.
Open your image in ACR (or your other RAW tool of choice) and adjust it for the sky to look nice.
Set some dramatic curve, set 0% sharpness, 100% smooth and 100% color noise reduction you know, the works.
Youll get something like this.
Nice dramatic skies but totally dark ground.
In fact, we may already like the effect, but lets assume that we do want the both parts of the image to be visible.
Lets get back to that RAW file, open it again and now make the adjustments that satisfy the bottom part of the image: crispy sharp grass blades, nice dynamic khaki colors of the trail and we end up with something like this.
Now the bottom part is fine (or, at least, we pretend it to be), but the sky portion is totally blown out.
What shall we do?
We blend the two images, in a normal mode, with the mask.
To do that, we bring them together as two layers (I usually prefer the ground being the lower one and skies being on top), add layer mask, select the linear gradient tool, and make a small gradient as shown by the arrow. I also left the guides visible to show the range of the blending. Voila! We got a next to perfect sunset shot, with the smooth dramatic skies and a nice, sharp, clear grassy trail.
Sometimes the gradient tool can be too straightforward. In this case we can let it do the primary job, after which we can select a nice big smooth soft brush and adjust the mask by painting it with white or black to hide our artificial tracks of the initial blend.
In the end, as you can see, even the Normal mode, the simplest blending mode of all, combined with the proper Opacity value and/or some masking, can deliver some very nice and often desired effects all that with minimal amount of efforts.
FillIf you take a closer look at the top of Layers palette, you will notice that right under the Opacity slider there is another one named Fill. Not only they do look similar, at first glance they also seem to work similar. In fact, you can redo all the above examples from this article using the Fill slider instead of Opacity and the results will be absolutely the same. So, whats the difference? The difference lies in a somewhat advanced issue called Layer Blending Styles. The topic itself is extremely large and cannot be covered in terms of this little tutorial. In fact were going to cover it later, style by style, once were done with the Blending modes. But as of now lets use one simple effect that would let us see the difference between the Fill and the Opacity.
Lets add a nice big bold Copyright symbol to our image.
Select the Type tool (T), your favorite font face (I used Times New Roman), large size (I have chosen 1296, the maximum allowed by PS) and enter the Copyright character ©. (On a PC: press Alt key, type 0169 on the numeric keypad, release the Alt. You can also use Character Map tool, or whatever alternative way you prefer.
Sorry, I have no idea how to do this on the Mac, but I suspect it's somehow possible, too).
Youll end up with something like this (you color may vary, but, as you will see just in a few seconds, it really does not matter).
In any case youll get a Layer Style dialog (i.e. its Drop Shadow portion).
Tweak it as your heart desires. I set the Angle to 135, Distance to 25, Spread to 15 and Size to 50. There is no right or wrong here, every image may call for a different set of settings.
Now, restore the Opacity back to 100% and set the Fill down to zero.
Lo and behold, we got something totally different!
I hope the difference between the Opacity and the Fill should be pretty obvious by now, but I still will put it in words.
Unlike Opacity, which controls everything related to the layer, Fill slider does not affect the Layer Styles, only the image pixels transparency. Styles, of Effects, remain, so to speak, unaffected.
Bottom LineNormal blending mode allows you to stack several layers on top of each other in a most intuitively understandable way, like the sheets of paper.
You can, however, modify this behavior by adjusting the Opacity of the layer, gain a greater control over the transparent areas by adding the Layer Mask, and if youre hardcore enough to work with the Layer styles, you can split the transparency control between the Opacity and the Fill sliders, the former affecting everything and the latter leaving the styles, or effects, unchanged.
You can discuss this tutorial or ask questions on Digital Grin.