Destructive editing has become the norm in Photoshop, where image layers are directly manipulated and pixels are permanently changed or deleted. RAW files are edited in Camera Raw, then opened as raster images, throwing away all the raw data in the process. You'd better remember to do everything you need to in ACR! What if there was a better way?
I switched back from Lightroom a couple of years ago because I prefer the power and adaptability of Photoshop, but I was disappointed with its limited non-destructive workflow abilities. However, recent versions of Photoshop make it extremely easy to achieve a non-destructive workflow by using Smart Objects.
I'm going to show you how the various aspects fit together into your post-processing. We'll be looking at opening RAW files as smart objects, re-opening in ACR, using Smart Filters for re-adjustable filter properties, and the use of Adjustment Layers in replacing some traditional tools.
1. What is a Smart Object?
Smart objects are vector or raster images, but not how you traditionally think of them. It would be better to imagine them as a RAW file for the image data. They contain the data and keep it infinitely manipulable by not allowing the original data to be altered or destroyed, only indirectly and externally transformed.
I've always used them in their most basic form as a method to resize composite layers without any data loss. The original image information is all there, so shrinking it with Free Transform doesn't destructively resample the layer. I could then enlarge it anywhere up to the original size and maintain sharpness.
Now I'm using them all the time. They're especially helpful with artificial lighting, as the ability to return and manipulate the RAW data more precisely once I've worked the image more heavily can sometimes be the difference between destroying an image with heavy effects and saving it with delicate RAW adjustments.
2. Opening Your RAW Smart Object
Camera Raw provides different options for opening image files depending on keyboard shortcuts. To open as a smart object, hold the Shift key and you'll notice that Open Image becomes Open Object. Shift-Clicking like this pulls all of the raw data from the image into Photoshop as well as your development settings into a smart object called Layer 0, instead of Background.
Ensure you have 16-bit image opening turned on in ACR. While it's theoretically possible to have 8-bit smart objects inside 16-bit PSD files, or have the original 14-bit RAW previewing as an 8-bit bitmap within Photoshop, it's easier just to keep everything at an appropriate colour depth. This also helps reduce the incidence of black and white conversions banding, and other 8-bit associated artifacting.
3. Inside Photoshop
Once ACR has transferred the developed RAW to Photoshop, you'll see Layer 0 appear, with a little smart object icon inside the layer thumbnail. This Smart Layer contains the raw image data, the development settings, and a bitmap version of the current version of the developed image.
If you want to re-edit the image in ACR, simply double-click on the layer thumbnail and Camera Raw will pop back up, just as before. You can do this at any time during your processing workflow.
4. Right-Click Options
There are some new right-click options when using a smart object. An interesting one is Replace Image. This allows you to browse for another image which will replace the one currently inside your Smart Object layer. This can be a re-developed version of the original image, particularly useful if you're using Lightroom to provide your primary RAW development environment and opening as a Smart Object from there.
It can also be a different image to the original, which will get imported in just the same as the previous image, and all the raw data will be contained with it. Rather than simply replacing the raw image data and updating the bitmap via the old image's development data, ACR opens for import just as if you were opening a new RAW file.
You can also export smart objects. If the smart object is converted from a raster layer, it exports as a smart object file (.psb). However, when the smart object is imported from raw camera data, the export dialog has the file format set to the original RAW filetype, such as .CR2, .NEF, etc.
This doesn't necessarily seem helpful, but if you're one of those photographers who likes to process and then delete RAWs, this is a method of recovering your original file without having it take up significantly increased disk space.
5. Duplicate with Care
When duplicating layers with smart objects, be careful how you do it. Simply hitting Ctrl-J or drag-and-dropping to duplicate the layer will result in an exact duplicate of the layer. This sounds like what you want, but the problem is it's a literal duplicate.
If you edit either layer in ACR, the changes will reflect in both layers. Sometimes that can be helpful, but if you want separate layers to do multiple RAW conversions or the like, make sure you right-click on the smart object and choose New Smart Object via Copy.
Once you have your smart object open and try to edit it, you'll soon realise that you actually can't. Things like Levels don't work, you can't dodge and burn, there's no painting, etc. The smart object is completely non-destructive, and thus will not allow direct manipulation of the pixels. There are, however, plenty of tools to allow manipulation of the layer. Smart Filters are our first stop.
7. Smart Filters
Many of Photoshop's filters have been adapted for use as Smart Filters, allowing them to be used on smart objects. The way a smart filter applies to a smart object is much the same way as Layer Effects. They get attached to the layer non-destructively, and can be turned on and off, double-clicked to edit parameters, and re-render if the layer gets altered.
For example, let's take Gaussian Blur, a staple of many Photoshop workflows. With a smart object, you hit Filter > Blur > Gaussian Blur. Just the same as normal, but now you'll note that a drop-down pops up on the layer, instead of the "fx" icon, it's two overlapping circles. This is the start of your smart filters stack.
Hit OK in the Gaussian Blur dialogue, and your smart filters stack will appear, with a mask thumbnail governing the stack. Double-clicking on the "Gaussian Blur" text will bring up its dialogue once again, with current settings. You can change the smart filter settings however you want, as many times as you want, no matter how much editing you do afterwards.
8. Manipulating Smart Filters
The mask for the filter stack allows you to mask off the effects you apply to the layer, but unless you nest duplicate smart objects by right-clicking, selecting Convert to Smart Object, and applying single filters to single objects within the nested stack, it's not possible to add multiple filter masks to a single layer.
The object nesting method seems tedious and time-consuming to re-edit to me, I just duplicate layers and add single filters to those. I find it easier to see everything at once.
It's also possible to adjust the blending mode of the smart filter. You can do this by right-clicking on the filter and selecting the pithy Edit Smart Filter Blending Options". This is how you would, say, apply a High Pass Smart Filter to an image in Overlay or Hard Light mode, for example.
9. Adjustment Layers
On to Adjustment Layers. These are much more popular now, so many of you may well be aware of their abilities. These are non-destructible layers which apply effects to the layers below them. They include Layers, Curves, Hue/Saturation, Color Balance, Black & White and Gradient Map.
They serve a variety of purposes, but a good example for this article would be to use Curves as a substitute for dodging and burning. By creating two Curves Adjustment Layers and setting one lighter and one darker, you can mask in the degree of effect from the adjustment layer you want, just as you would paint on the tonal adjustments.
An advantage of this technique, whether you're using smart objects or raster bitmaps, is that you can never over-cook the dodging and burning, as you've set your upper and lower limits into the curves adjustment layers.
The other adjustment layers are quite handy too, but remember, many of them are now available within the smart object in Camera Raw, so there's no need to edit a 16-bit bitmap when you could have access to raw camera data!
10. Heavy Lifting
Remember, the bulk of these effects, filters and manipulations are graphical transforms on the mathematical level. Because everything must re-render every time something's changed underneath it, you'll need a computer with good grunt so as not to slow down your artistic process, especially when piling on the layers and megapixels. A fairly recent CPU and a solid graphics card (GPU) are fairly important.
Don't forget either that you're duplicating your RAW data into the PSD file, so file sizes aren't going to be too small. Storage is fortunately fairly cheap these days, but ensure you have a well organised backup system in place for the increased volume.
That's a Wrap
That's all for now. I've looked at smart objects and how you can use them to retain your raw image data, as well as the basics of a smart object based workflow and how to go about the rest of the processing with smart filters and adjustment layers once your smart object layers are set up. I hope you found this article helpful, I'm certainly enjoying the freedom offered by the improved features for smart objects!
Questions? Comments? Hit up the comments below!