Join Jan Kabili for an in-depth discussion in this video Adjustment layers vs. direct adjustments, part of Photoshop CS4: Image Adjustments in Depth.
Most tonal and color adjustments in Photoshop can be applied to an image either is in adjustment layer or as a direct adjustment that's made right on the image. Whenever you do have that choice the adjustment layer method is the best way to go, because adjustment layers offer at least six unbeatable advantages over direct adjustments, which I'm going to cover in this movie. The biggest advantage of an adjustment layer is that it is non-destructive of the original image as I mentioned in the preceding movie. So in this case for example, I have made a Brightness/Contrast adjustment on this adjustment layer.
But doing so, hasn't changed or damaged the pixels on the affected image layer below. A second advantage of making adjustments in an adjustment layer like this is that the adjustments remain editable. So if I did want to change the amount of brightness or contrast that I've added with this adjustment layer, I can get my adjustment controls back by just clicking on the Brightness/Contrast adjustment layer or if my Adjustments panel isn't open already, I can just Double-click on the leftmost thumbnail on the Brightness/Contrast adjustment layer, to both open the Adjustments panel and bring up the controls for this adjustment.
Once I have these controls available, I can click and drag on either of these sliders to change the adjustments, and I can do this as many times as I want without degrading the image. Another advantage of working with adjustment layers in Photoshop CS4 is that in this version of the program, I can access other controls when the adjustment layer settings are open as they currently are here in the Adjustments panel. So for example, I can move back and forth between these controls and the controls at the top of the Layers panel. With the Brightness/Contrast adjustment layer selected, I could change the way that adjustment is blending with the pixels on the image layer below. By going to this layer blend mode here and choosing a blend mode or even Normal.
I am going to go ahead and choose Soft Light, which is a blend mode that increases contrast. I also could change the strength of this Brightness/Contrast adjustment by going to the Opacity field here, clicking the arrow to the right of that field and lowering the Opacity of the Brightness/Contrast adjustment and then clicking off of that slider. And I can still go back up to the Brightness slider and tweak it similar. This ability to move back and forth between controls in the Adjustments panel and other image controls is something you couldn't do with adjustment layers in earlier versions of Photoshop, and it's something you still can't do with direct adjustment. His is a welcome new feature that will seriously bump up your efficiency when you are with adjusting with adjustment layers.
Another benefit of adjustment layers over a direct adjustment is that an adjustment layer comes with a layer mask, which you use to limit the area of the image that's affected by the adjustment. So in this case, you can see that there is a layer mask thumbnail on the right side of the Brightness/Contrast adjustment layer. I've gone ahead and created a gradient inside of that layer mask that's limiting the application of this Brightness/Contrast adjustment where the layer mask is dark at the top of the image. I've show you exactly how to do that in a later movie I'm working with working with layer masks and adjustment layers. But for now I'd like to tell you one more benefit of using an adjustment layer over a direct adjustment and that is that after you correct one image with an adjustment layer, you can easily apply that adjustment layer to other images even if they are images that have different resolutions. And I'll be showing you how to that in a separate movie later in this chapter.
Now for comparison, I'd like to show you what happens if I try to apply a similar Brightness/Contrast adjustment directly on the image layer rather than by using in adjustment layer. So I'm going to come down to the Layers panel and make the adjustment layer temporarily invisible by clicking its eye icon. Then I'm going to select the image layer in the Layers panel and to apply a direct adjustment on this image layer, I go up to the Image menu at the top of the screen and down to the Adjustments menu, then I move over and I'll choose Brightness/Contrast.
That opens a separate dialog box where I can tweak the Brightness or the Contrast of the image. One disadvantage of working this way is that while this dialog box is open, I can't come into the Layers panel and access the layer blend mode or change the Opacity or the Fill. Those controls just aren't available while a direct adjustment dialog box is open. I am going to click OK, to apply this Brightness/Contrast adjustment to the image layer and that brings up yet another disadvantage of working with direct adjustments, which is that this adjustment has directly changed the pixels on the image layer and I no longer have access to my original unchanged photograph.
I could undo this adjustment, but once I've saved and closed this image, the direct adjustment will be permanently baked in. I also can't go in and edit the adjustment I just made. The best I could do is to go back to the Image, Adjustments, Brightness/Contrast again, and notice that my sliders have gone back to 0. So if I do make a change here, it would be accumulative one on top of the initial adjustment. So I'm going to click Cancel to close this dialog box. I'm going to open that menu of direct image adjustments again, by going up to Image, Adjustments and take a look at the first fifteen of these adjustments, all away from Brightness/ Contrast down to Selective Color. Any of those could be applied with an adjustment layer rather than as a direct adjustment, and that's what I recommend that you too for these fifteen adjustments.
There are a handful of adjustments at the bottom of this menu from Shadow/Highlights down to Equalize that can only be applied as direct adjustments. Fortunately, these aren't the most frequently used adjustments. Of these Shadow/Highlights and Variations are probably the adjustments that you'll use most. And fortunately, there is a workaround that will let you apply these two kinds of direct adjustments in a non-destructive manner, which I show you how to do in later movies in the course. So please do use adjustment layers over a direct adjustments whenever you have a choice. Adjustment layers are the corners stones of a flexible re-editable and nondestructive workflow that ultimately will save your time and effort.
So I do recommend that you use them liberally.
- Using adjustment layers in a non-destructive image-editing workflow
- Correcting color with curves
- Adjusting brightness and contrast with levels
- Dodging and burning photographs
- Reading histograms accurately
- Converting color images to grayscale with a Black & White adjustment layer
- Customizing auto-corrections for more accurate quick adjustments