Basically, Smart Objects are just layers. However, Smart Objects are not ordinary layers; these layers have very unique properties. The most important thing to understand about Smart Objects is that a Smart Object completely preserves the image data. In other words, no matter what you do to a Smart Object, there is always a copy of the original data. Thus, Smart Objects can always access the original data. A key result of this is that Smart Objects allow for nondestructive editing of images that were created as Smart Objects in Camera Raw.
The first step to using Smart Objects for nondestructive editing is to open a raw file in Camera Raw. This is done by choosing File/Open and accessing the file (see Figure 1).
The raw file is quickly opened in Camera Raw (see Figure 2). Right now, the image looks rather flat. That will be worked on in a bit.
Now, at this point, it is very important to understand a crucial point: all edits performed in Camera Raw are nondestructive. This is the key to the entire process of nondestructive edits with Smart Objects.
The next thing that needs to be done is to make sure that the image will open in Photoshop as a Smart Object. For that, the Workflow Options below the image is clicked (see Figure 2).
The image is now opened in Photoshop (see Figure 5).
As can be seen in the Layers panel, the image has a single layer (see Figure 6). The tiny Smart Object symbol in the lower right hand corner of the layer icon indicates that this layer is a Smart Object.
At this point, an evaluation of the image indicates that the image could use some more contrast and perhaps a bit more saturation.
In other words, there is some more editing work to do. Now, since this image was created as a Smart Object, further edits can be performed in Camera Raw. This is done by reopening the image in Camera Raw by double clicking the Smart Object layer. Figure 7 shows the image back in Camera Raw.
Now, it is important to understand the significance of what was just done. Since the image is a Smart Object that was originally converted in Camera Raw, the image can be reopened in Camera Raw for additional editing. Since all edits in Camera Raw are nondestructive, this means that the new edits will be nondestructive. The point here is that Smart Objects allow for nondestructive editing because they allow images to be reopened in Camera Raw where the editing is nondestructive. If the image was not a Smart Object, it could not have been reopened in Camera Raw.
So, multiple edits were carried out on this image, and it was all done nondestructively. Furthermore, the edits could continue like this all day. No matter how many times the image went back into Camera Raw, no matter how many edits were made, no matter how strong the edits were, it would always be nondestructive.
While the combination of Smart Objects and Camera Raw is a very powerful option for nondestructive editing, Smart Objects can be used for other types of nondestructive editing even when an image was not created as a Smart Object by Camera Raw.
In fact, at this time, the image of a beach scene (see Figure 10) isn’t a Smart Object at all. This is obvious because the only layer in this image is missing the Smart Object symbol in the lower right corner of the layer icon (see Figure 11)
One of the key advantages of having a Smart Object is that transformations are nondestructive. This can be demonstrated by applying a scale transformation, two times, and analyzing the results.
The scale transformation changes the size of the image. The transformation is performed by choosing Edit/Transform/Scale. The transformation now allows the image to be scaled by grabbing one of the corners and dragging (see Figure 13). For this transformation, the image will be made very small.
After the dragging is complete, the transformation is completed by hitting the Enter key. The image now appears as seen in Figure 14. The image is currently very small. Now, this may seem a very odd thing to do. Why would anyone want to reduce an image to such a tiny size? Well, in ordinary editing, there isn't much need for such a radial scale transformation. However, for this demonstration, it has a purpose as will become clear in a moment.
The next step is to perform another scale transformation to return the image back to its original size. So, once again, Edit/Transform/Scale is chosen, and one of the corners is dragged back to its original position. After the Enter key is pressed, the second transformation is complete (see Figure 15).
Okay, so what is the point of all this? The point of this is that, because the image is a Smart Object, the image always has access to the original data. Consequently, the two transformations that were performed on this image were completely nondestructive. This can be seen in Figures 16 and 17. Figure 16 shows the image before the scale transformations. Figure 17 shows the image after the transformations. As can be seen, the images look exactly the same. In fact, they are the same. No image degradation occurred because of the two transformations -- even though the transformations were rather extreme.
For comparison purposes, the same two transformations were performed on the same image except the image had not been converted into a Smart Object. Figures 18 and 19 show the image before and after the two transformations. As can be clearly seen, when the image was not a Smart Object, the transformations caused massive image degradation.
At this point, it should be obvious that Smart Objects provide a powerful, nondestructive method of performing transformations. Furthermore, while this demonstration used scale transformations, there are many other types of nondestructive transformations that can be done with Smart Objects.
More nondestructive editing techniques will be examined in Part III of this article series. In addition, an editing method that does not cause any image degradation will be introduced.