Photoshop Fundamentals – Understanding Layers

In General - Post Processing, Landscapes - Post-Processing, Learning Center by jfischer1 Comment

Making the jump from Lightroom to Photoshop can be an intimidating proposition.  Much like that first time you switched the camera from Auto all the way to that frightening ‘M’, suddenly you had more tools to work with than you knew what to do with.  No longer was the camera handling everything behind the scenes and making the majority of the decisions for you; now you had to know the correlation between Shutter Speed, Aperture and ISO to make the image you wanted.

While Lightroom isn’t exactly the ‘Auto’ of Post Processing workflows, far from it, it does abstract some things away in the name of ease of use. Lightroom is a fantastic piece of Image correction software. It allows both a huge amount of improvement of both RAW (and heaven forbid) JPG images and I still heavily use it at the beginning and end of my post processing workflow. The main thing to remember is that Lightroom is a completely non-destructive editing process. Your original image is never touched, rather Lightroom simply gathers up the current position of every slider and selective adjustment you’ve made and in real time shows you the result on your screen. It does have it’s limitations in the scope and flexibility that an image can be adjusted, even with the additions of range masking for its selective editing tools. In Lightroom’s global adjustments, the order of operations doesn’t matter, you can adjust the sliders in any order you want, as often as you’d like, and your image will look exactly the same as if you adjusted them in any other order.  

Lightroom’s Basic Panel – that I tweaked and tweaked over and over again.

One of the first things you’ll discover when making the transition to Photoshop is that your image sits in a panel off to the right side labeled ‘Layers’.  Layers are, without doubt, the single most important building block of the application.  And it can be one of the most confusing to understand at first, but once you master it, the first key in opening up the vast toolbox that is Photoshop will be in grasp.

I’ve heard Layers explained in a great number of ways, from ‘sheets of paper’ to ‘sheets of film’ to ‘panes of glass’, and so forth.  When I open an image in Photoshop either from Lightroom or Adobe Camera Raw, I start with a fresh clean ‘print’ of my RAW file sitting on the work space. Coming from Lightroom I right-click on the image, ‘Edit-in’ and select Photoshop CC. That is your ‘Background Layer’.  That’s your starting point for everything else you’re going to do in Photoshop, a crisp clean copy of your image sitting on the desk. Note: Unless you are using a Smart Objects, you are no longer using your RAW file in Photoshop, rather a TIF. Thus having as much dynamic range in the image as needed is vital before starting in Photoshop.

Image Adjustments – They are destructive!

Coming from Lightroom, you might first dig through the ‘Image’ menu in Photoshop until you find something called ‘Adjustments’ and find things you’re familiar with: Curves, Levels, Saturation, Exposure, lots of adjustments.  Here is where the first critical difference between Lightroom and Photoshop is – adjustments done directlyto your Background layer are destructive.  Make one saturation adjustment drop it to 0, that’s done, finished, only way back is the history/undo, no amount of additional saturation adjustments is going to get you back to where you started.  Likewise, make an exposure adjustment too far and blow out your highlights; they’re gone, and not coming back by making MORE adjustments.  You get the idea.  However, since the title of this article is ‘Layers’, about now you’re probably guessing there’s a better way.  And there is.  And yes, it’s layers!

There are two types of layers in Photoshop that behave in very different ways. The first is a pixel layer. You’ve already been introduced to your first pixel layer – the ‘Background’ layer that Photoshop loads your image onto. You can create duplicates of this layer, you can create empty (transparent) layers that you can draw on, fill layers with solid colors, etc. Pixel layers are the sheets of film/glass/etc contain luminosity and color. The second type is the Adjustment Layer. These do not contain pixels, but rather makes an adjustment to how you see the pixel layer under them. So, adjustment layers don’t contain pixels, they adjust them.  Clever naming, I know.  Think of them as the control knobs for the luminosity and color of an image. You can add as many of these controls as you want on top of a pixel layer, turn them on, turn them off, turn them up and down, and the pixel layer under it is not directly affected. So you could say that Lightroom is one giant ‘Adjustment Layer’ sitting on top of a pixel layer with all of the controls in one. Photoshop breaks these up into many layers, letting you add them one at a time. The other prime difference is that the order of adjustment layers in Photoshop does matter. If you create one Hue and Saturation adjustment layer with -100 Saturation and then another with +100, you’re still going to have a monochrome image.

Back to your example edit, instead of making the adjustment directly to your image layer, we’re instead going to create an ‘Adjustment Layer’.  There are nearly as many different types of Adjustment Layers as there are ‘Adjustments’ in that evil ‘Adjustments’ Image menu.  I think of these as clear sheets that you lay on top of your original ‘print’ that modifies what you see underneath.  Throw a curves layer on above your image, make a big fat S-curve and your image is more contrasty.  Now add a Color Balance adjustment layer on over the curves layer and you can make those adjustments, and so forth.  Remember, the order of your layers does matter, since each adjustment layer makes adjustments on how it sees the entire stack of layers below it.  A Levels adjustment placed on the top of the stack will make the image look different than if the same exact layer was re-positioned lower in the stack depending on what else is in between. 

Adjustments Tab – but there’s a quicker way…
Adding Adjustment Layer from Toolbar Menu – this is how I add layers 95% of the time
Properties Window allows for modification of your adjustment

Decide that you make that curves layer too drastic, no worries, click on the Curves Layer and readjust it.  Since you are making changes to the Adjustment Layer, and not your image on the bottom of the stack, you’re not affecting it, just how you see it – a lot like you were back in Lightroom, just now you have consider the order in which each adjustment is applied.  And that my friends is the key, layers allow you to affect how you see the image, as you look down through all the layers.  You can see all the way down until you hit a solid pixel, which if all we have are adjustment layers, is down to your Background pixel layer on the bottom.

Speaking of seeing all the way down to the bottom, what if there was some nagging little flaws in your photo, twigs, bubbles on the water, that kid that wouldn’t get out of your shot at the Grand Canyon, you know, those distractions that you don’t want the viewer to focus on?  You could merge everything together, remove the problem items with the spot healing brush, but then you’d have no ability to further refine those layers you just made.  Instead, set those nice layers aside (ie, turn them off by clicking on the little eyeball on the far left of the layer), going back to your original layer, either right-click on your background layer to choose ‘Duplicate Layer’ from the menu, or type command-J (control-J on PC) with the Background layer selected to duplicate it. Now you have two copies of your original photo, one stacked right on top of the other.  Since the duplicate is sitting on top, you can’t ‘see’ through it, even though the original ‘Background’ layer is sitting right underneath. We will call this duplicate background layer the ‘Cleaned Background’ layer. You can do anything you want with this duplicate, and the original is safely stored just below in case you need it.  In this case, I want to use the Spot Healing tool to remove most of the imperfections from the water or some dust spots for your sensor, or a twig sticking in from the edge.  If you mess up, you can always delete the ‘Cleaned Background’, make a new duplicate from your original Background, no harm-no foul.

Duplicate Background for Clone/Cleaning

Once your cloning is complete, turn on each of the adjustment layers again to bring all the layers back in place just the way they were, and now they are applied to your new cleaned up pixel layer.  You can also turn on/off the ‘Cleaned Background’ background layer, effectively ‘pulling it out of the stack’ to see the difference the spot healing made to reducing clutter.  When making spot-healing fixes, I routinely create new duplicate layers as I go along, just in case I want to put something back, or get too deep in the weeds trying to fix something and don’t want to lose all my changes if I throw away the layer. My own clone-history-save states.

Pixel layers are useful for more than just containing your background layer at the bottom of a huge pile of adjustment layers. Empty pixel layers have a lot of uses as well. Below your layers stack, a couple icons to the right of where you add Adjustment Layers is an icon nestled between the ‘Group’ and ‘Delete’. This creates a new blank pixel layer. Left click to create a new empty default layer, or hit Alt plus click to bring up a dialog with some options. For our demonstration purposes, Alt-click to get the menu and choose ‘Soft Light’ from the Mode dropdown, and then click ‘Fill with 50% Gray’ and click OK. If you look at your image really carefully… nothing happens. Your image is sitting there looking exactly like it did before you put a 50% gray, 100% opacity pixel layer right on top of everything. I cover blending modes more in articles including Dodge/Burn with Photoshop Blend Modes, but to keep our focus on the basics of layers, just know that 50% gray is ‘neutral’ to this blend mode, making it effectively disappear. At the top of your panel window, you’ll see the blend mode drop-down window displays the mode ‘Soft Light’ instead of ‘Normal’ as you’ve seen on the rest of your layers. So what’s useful about a layer that is invisible? Because you don’t have to leave it gray! Using the brush tool, set to a white (or other light color), and a low (20-30%) opacity and 0% hardness, you can ‘paint’ in ‘light’. As long as your brush color is brighter than 50% gray, the areas you paint on will lighten, if it is darker than 50% gray, it will darken. And the closer to 50% gray it is, the smaller the effect (though it’s easier to adjust that with opacity than the actual color in my experience). This technique is known as Dodging and Burning. While Photoshop has built in tools labeled just those two terms, using Soft-Light or Overlay blend modes on a blank or 50% gray layer allows better control, flexibility, and the ability to dodge and burn in COLOR.

A new pixel layer set to Soft Light
Layer 2 – my new Soft Light Layer as shown in the second dropdown in the Layers window.

With a few more adjustments which I will discuss in much more detail in a later article, here is the finished transformation to show what just a handful of layers can achieve, all while staying completely non-destructive to the original image, safely stored there at the bottom of the stack.  Which brings us to the last point, what to do when you’re done.  Outside of Photoshop, most other applications don’t know about nor understand layers, especially if you save your file as a .psd.  You certainly can’t upload your finished image to Facebook or Instagram or your website album like this for a number of reasons, one of which being the sheer size of the file regardless of final file format. The easy answer is to take the finished image back to Lightroom which does understand and correctly display layers. My workflow has all photos starting and ending back in Lightroom, so the simple answer is to save your finished image, as a .tif or .psd (I prefer .tif), which automatically adds it back to your catalog right along side the original RAW file you brought into Photoshop.  Let Lightroom be your engine for exporting the finished file into a format for distribution across the globe.  

Final Touches – how many layers?

Ready for more?

Want to learn more about how I use layers, and what layers I use for what purposes?  I have more free articles here on my website to explore covering a variety of topics, as well as offering one-on-one post processing and photography tutorialsContact me today to inquire about these services.


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