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Channels are an area of digital imaging that confuses many users. My guess is that this is because channels essentially represent something else. Guess what it is? Selections. This creates a bit of a conceptual disconnect for many. In this video, I will try to clear up the mystery of channels for you. Now, if you remember in our last video, we created a selection that's fairly sophisticated using the Magic Wand, and then I went in and used the Lasso tool to eliminate a little bit of extraneous selection by the Magic Wand itself.
One of the things that's important to note, that if we go to the Select menu, you can come back here and you can say Reselect. So I'm going to reselect that area. Now, that won't forever be there for you, it depends on whatever the last selection you made was, that is what is going to be available to you using the Reselect command. And I may want to, in this case, save this selection, because it took a little bit of work to get it, rather than have to redo the whole operation again. It would certainly save time if I could get back to that selection anytime I wanted.
And in the Select menu once again, we have the Save Selection command down here at the bottom. So if I say Save Selection, and I am going to save it to a new selection, I just want to say, I will call it deck. And we'll say OK. And now I can go ahead and use Command+D or Ctrl+D to delete that selection. But let's say it's later in the day and I no longer have Reselect available to get it, I have made many selections. I can now go down to Load Selection, and this is where I can go in here and Layer 1 Transparency just happens to be associated with this layer in the palette here.
But there's also the deck one. So I am going to say, I want to load deck, and there it is. So you can load and save selections. But the way they're really being saved, if we go over to the Channels palette, you will see that right there is that same area of the image, it's just, it's saved as a channel. And that's where this really gets people mixed up. One way to think of it is, that channels and selections are really two sides of a coin, and whenever you make a selection you're literally creating a channel or sometimes referred to as an alpha channel, and whenever you work with tools to create alpha channels, you're also creating selections.
Both of them are created using 256 shades of density, and that is represented by a grayscale, which extends all the way from black to white. And you can think of them as masks with varying transparency in them. So rather than a traditional mask that's either black or white, this mask has varying degrees of density in it and using that mask, you can allow varying degrees of color information, for example, to come through that mask. Now, one thing you want to remember, and this is what's important, you can see right here how there's some areas are black and some areas are white, in fact I can turn this on so you can see it.
It's just it's red in this case and we will end the selection here. So if you look inside the representation that we see inside the Channels palette, what is red here is black. And everything that's transparent is white. One rule of thumb to remember, so you don't get mixed up about which side of a selection is revealing or hiding, is the simple phrase, white reveals black conceals. So anywhere it's white, and again if we just look at the representation in the Channels palette, white is where we are letting the original color of the image come through and anywhere it's black, or red in the case of the large display over the image, that is where it is being protected, and that's exactly what's going on with the selection.
So you can either look at it this way, or you can turn this off, and when you select this, now there you see, in that form, black and white. This is a very dramatic look at how the white is what's letting it through, and the black is hiding it, and once we turn it off, you can see it back in its normal mode again. So the basic idea here is that what you think of as an alpha channel is really just another way to store a selection. In fact, every time you store a selection, whether you actually do it as a channel or not, it's internally saving it in the same fashion as when you overtly make a channel from a selection.
And you can go the opposite direction. You can use masking tools, for example, to paint an alpha channel, and then you can convert it into a selection. And that's because, as I said, there are simply two sides of a coin representing the same concept.
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