“Destructive” Adjustments


Today’s Question: From Tuesday’s eNewsletter: “By default, as with other filters in Photoshop, the Camera Raw Filter will directly alter pixel values.” I know this is true but I would be hard pressed to explain it to anyone using Photoshop. Can you discuss this effect?

Tim’s Quick Answer: When pixel values in an image are modified directly, this is often referred to as “destructive” processing. What this means is that the pixel information in the source image is being altered directly. The alternative would be a non-destructive workflow, where the adjustments are saved as information separate from the underlying pixel information.

More Detail: As noted in Tuesday’s Ask Tim Grey eNewsletter, filters in Photoshop directly alter pixel values. This approach can reduce the flexibility of your workflow, which is why I generally recommend a non-destructive approach to optimizing your photos whenever possible.

The key risk of a destructive workflow is that you won’t be able to return to an earlier version of a photo. For example, let’s assume you applied the Camera Raw Filter directly to an image rather than as a Smart Filter. If you use the filter to convert the image to black and white, and then save and close the image, you will have permanently removed the color information from that image. Unless you have another copy of the image you won’t be able to create a color interpretation anymore.

By contrast, if you apply the Camera Raw Filter as a Smart Filter (as outlined in Tuesday’s Ask Tim Grey eNewsletter), you can later return to the filter settings to refine your work or return to an earlier version of the image.

It is worth noting that when you process an original raw capture (such as with Camera Raw, rather than the Camera Raw Filter) you are always working non-destructively. That is because the adjustments you apply with Camera Raw in this context are used to render a new image based on the original raw capture, and do not overwrite the pixel information contained within the raw capture itself.