Today’s Question: In Photoshop is it better to use the adjustments or the adjustment layer function on an image.
Tim’s Quick Answer: I recommend using adjustment layers instead of direct adjustments in Photoshop, saving the resulting “master image” as a Photoshop PSD or TIFF image file to preserve those layers for future refinement.
More Detail: I recommend using adjustment layers whenever possible for the adjustments you apply within Photoshop. There are a couple of key reasons for this, which mostly involve ensuring you are maintaining maximum quality for the image as well as flexibility in your workflow.
When you apply an adjustment directly to an image in Photoshop, you are altering the actual pixel values in the source image file. When you use an adjustment layer, you are preserving the original pixel values in the source image file, and simply adding information to the file about the changes in appearance you want to have applied. The appearance of the image will change in Photoshop, but the source pixels remain as they were. Printing or otherwise sharing the photo will result in an appearance based on your adjustments.
By working with adjustment layers, the greatest benefit is that you can always return to your master image file as long as you’ve preserved the adjustment layers as part of the file you save. You can then return to that file at any time and make changes to any of the adjustment layers without negatively impacting image quality. This gives you great flexibility in your workflow, since you can always return to the master image and refine your adjustments.
In addition, using adjustment layers can help prevent a cumulative loss of image quality for the photo. For example, let’s assume you had increased the contrast significantly with a direct adjustment to an image. You later decide you that you want to reduce contrast. Applying an additional adjustment in this context will not result in a photo that has as much detail as when you started, because some of the detail was lost when you increased contrast.
In addition, there can be a degradation in image quality by applying multiple adjustments to an image. Because an adjustment layer doesn’t directly alter the underlying pixels, that adjustment layer only counts as a single adjustment, even if you refine the settings for the layer multiple times.
As a result of these issues, I strongly recommend using an adjustment layer for any adjustment that is available as an adjustment layer in Photoshop. You can then save the image as a Photoshop PSD file or a TIFF image with layers intact, so you can return to the image later and refine any of the adjustment layer settings if you’d like.