Converting to black and white using Black & White adjustment layers

So far, I've been applying the black- and-white conversion tool by opening an image and going up here to Image > Adjustments > Black & White, and when I do that--like I am doing right now, and this is just the same thing we've seen before-- I'm going to make a couple of adjustments to the sliders, hit OK, and when I do, the black-and-white adjustment is applied to my color image in a destructive manner, meaning my original pixels are irrevocably altered. The color image is gone; this is now a black-and-white image. Yes, I can undo to get back to my color image, or redo to get back to black and white.

But as soon as I make one more error, I can't do that anymore. And if I save the image then for sure it is henceforth a black-and-white image. The problem with that is if I want to keep the color version I have to keep separate files and so on and so forth, and more importantly, if I decide well, I'd like to darken that blue sky a little more, I can't get back to those tools in any way. So, a much better way to apply the black- and-white conversion in Photoshop is to do it through an adjustment layer. Adjustment layers are Photoshop's mechanism for applying certain edits in a completely non-destructive manner, meaning that you can go back and alter them or remove them later.

If you're not familiar with adjustment layers, we'll do a quick run-through right now. Here in my Layers palette, I have a background layer. That's my image. Down at the bottom, I have the little circle that's half black, half white. That's a pop-up menu. If I click on it, I get this list of things. And they're all operations in Photoshop that I can apply as an adjustment layer, so I am going to pick Black & White. And when I do, my image goes to grayscale with the default black-and-white recipe, and my Adjustments panel up here fills with these black-and-white controls just like we saw in the Black and White dialog box.

Now, if you're using Photoshop CS3, you won't have this Adjustments panel; instead, you will simply get the Black and White dialog box like we saw earlier, you configure it, hit OK, and then your adjustment layer appears down here, just like we've got here. Now notice my color image is still here. There is just now a layer sitting on top that's doing the black-and-white conversion. This little eyeball controls visibility. If I turn that off, you see my color image. Turn it back on and there is my black-and-white image. You can think of this Black and White layer as some kind of like magic transparency that you're setting on top of your color print, and when you do that, it converts into black and white-- or maybe a can of black-and-white spray paint of some kind; you spray it on your image and wherever you spray, the image goes grayscale.

So what's cool about this is I can hide it. I can, if I want, remove it completely and go back to my color image and undo that. Also, if I adjust my parameters up here--and we'll do the same edit we've been doing. I'll darken the sky up a little bit. I'll lighten that red tree, and I will darken the greens. Let me just mention to get this Eyedropper tool like we had in the Black and White dialog, you have to click on this thing. So I have to select my adjustment layer, then click on this thing, then I can go up here and drag with the eyedropper to alter my parameters.

Now what's great about doing this as an adjustment layer is these parameters will always be alterable. I can save the image, shut it down, close it, go to launch, come back, and I will still be able to adjust these parameters later. So if later I do a print and decide well, the sky needs to be a little bit darker, or I've got a little bit of banding here in the sky, I actually need to back off of that edit, I can go and change these parameters at any time to further alter my image. I cannot do that if I do the destructive edit through the normal dialog box. So through the rest of the course I will be applying the black-and-white adjustment using an adjustment layer both because it allows me to undo it later and it allows me of this parametric editing, the ability to go back and adjust parameters later.

There's one other cool thing about the adjustment layer that we are going to see later, and that's the ability to selectively change my image to black and white. So fiddle around with this and get use to the Layers interface and the Adjustment panel interface and make sure you're comfortable with them before we go on.