Today’s Question: Can you clarify what you mean when you say that using a Smart Filter [in Photoshop] can cause problems with a layer-based workflow? The feature sounded great until I read your warning!
Tim’s Quick Answer: The problem with using Smart Objects (including Smart Filters) in Photoshop is that making changes to that Smart Object can cause other pixel-based layers to no longer match the overall image.
More Detail: Smart Objects in Photoshop represent a powerful and helpful feature. However, there is an important shortcoming that can lead to significant problems with layer-based images.
When you create a Smart Object (or apply a Smart Filter) you are effectively embedding an image within the overall document. The benefit of this approach is that you maintain the ability to modify the embedded image, since the original is there as a reference.
For example, let’s assume you’re using the Camera Raw filter as a Smart Filter, as explained in yesterday’s Ask Tim Grey eNewsletter. You use the Camera Raw filter to convert the image to black and white. However, since you used a Smart Filter, you can go back and change the adjustments at any time. So, you double-click the Camera Raw Filter layer and switch the image back to color.
This is all perfectly fine, and it helps illustrate the power of Smart Filters. However, there is a potentially significant problem.
Let’s assume that after using Camera Raw as a Smart Filter to convert the image to black and white, you decided to perform some image cleanup work to get rid of some blemishes and distractions in the image. Wanting to maintain a non-destructive workflow, you create a new empty image layer to use for the image cleanup work.
After performing the image cleanup work, you go back to the Camera Raw Filter layer, bringing up the Camera Raw dialog. At that point you convert the black and white image back to color and apply the change.
At this point the underlying image based on the Smart Filter is a color image. However, the image cleanup work performed on a separate layer was done while the image was in black and white. Therefore, the cleanup pixels are in black and white, but the image is in color, so there is a very problematic mismatch.
So, while Smart Objects in general and certainly Smart Filters in particular can be incredibly helpful, they can cause problems in a layer-based workflow. In the example above, I would want to spend time fine-tuning the Smart Object to perfection so I feel reasonably confident that no further adjustments will be necessary. I would then move forward with any work that required other pixel-based layers, such as to perform image cleanup with the tools in Photoshop that are more powerful and flexible than what is available in Camera Raw.
