Digital photographs are made up of pixels — "tiny dots". Photoshop is about editing pixel images hence editing photographs.
If you continuously zoomed in on a photograph you will eventually see individual dots or rectangles — the individual pixels. A typical reasonably good camera might have a pixel resolution (dimension) of 6000 × 4000.
Photoshop is a vast application that has evolved over many years. It is huge in terms of functionality and I doubt that anybody really knows all of Photoshop.
Here I teach those parts of Photoshop that I myself use: the really useful bits for a web and graphic designer and photographer (serious photographers would use also Lightroom Classic, which is not covered here).
I will divide what I teach in Photoshop into two sections:
- Image adjustments: adjusting things like white balance, exposure, contrast, saturation, cropping, etc., and in modern times these are done mostly in Photoshop Camera Raw (the Camera Raw Filter), even when you are not working with a RAW image.
But the Photoshop Camera Raw engine has become so powerful that the distinction between adjustments and manipulation is no longer that evident — so adjustments now include some manipulations. - Image manipulation: this is when one cuts out portions of images, uses layers, retouches, and does many wonderful things within the main Photoshop space. Also, included here are Photoshop’s powerful new AI tools, like Generative Fill and Remove.
I will also go through how to easily make sophisticated mock-ups using pre-made PSD template files (see the Bits and Pieces page) — this does not fit into the neat categories above.
Note that some things that one can do in Photoshop, like build a composite layered graphic or tint an image, can be done equally well in InDesign. In InDesign one can better see the desired end result in the context of a document.
1. Opening an image and exploring the workspace
Download the class material from qoolcat.com/down/photoshop-1.zip.
Unzip the file which is in a single directory (a folder with files in it) by double-clicking on the ZIP file.
Open the image “1_baboon.jpg” in Photoshop.
(To open, right-click on the file then go .)
▷ So that we are on the same (useful) workspace, go .
(A Workspace is an arrangement of Workspace Panels and Meu Bar — and Photoshop offers several workspaces.)
Note that, when you update an Adobe application like Photoshop, the workspace might revert back to the default, so you again then need to set the workspace.
This is what you should be seeing in Photoshop…
And, besides the actual image, note the four main elements…
Menu Bar: this is a standard menu bar like in all other applications.
Tools Panel: all the tools, many of which you will soon become familiar with. If a tool icon has a small triangle in the bottom-right corner, then pressing on the tool reveals more tools (“underneath”). See the example below.
Control Panel, also called the Options Bar: this changes depending on what you are doing so becoming like a very large context menu — it is very useful.
Workspace Panels: these are arrangements of tables and visualisations with parameters, for accomplishing much of the heavy work, which will become obvious in the next Photoshop lesson.
Contextual Taskbar (not shown above): a context-aware bar that floats on your screen, offering common tools, actions and next steps on the canvas where you’re working. You can drag this bar to another location if you want. Often, the next steps shown in the lessons will be available from this bar. To show or hide the Contextual Taskbar, right-click in the workspace, outside the image.
See the image zoom amount bottom-left (which in the above example is 67%).
▷ Go ⌘0 (command+zero) to have the image fill the workspace available
▷ ⌘1 to see the image zoomed to 100%
▷ ⌘+ to increase the image size; ⌘- to decrease.
▷ You can also pinch and unpinch on your trackpad to change the image zoom.
These key shortcuts work the same in InDesign and Illustrator.
2. Cropping and levelling
Suppose that, for the baboon image, you want (1) the top of the roof to be horizontal and (2) a crop ratio of 4:3.
▷ In the tools panel, click on the Crop Icon (as shown here), or go C for crop.
▷ In the options bar, make the ratio 4 and 3 (for 4 wide to 3 deep), and check that Fill is set to Background (default).
▷ Place the cursor just outside of the image area and you will see a two-arrowed icon. Drag on the two-arrowed icon to rotate the image, and make the roof horizontal.
▷ Crop to your taste by dragging the crop handles, maybe cropping out some of the roof foreground, and moving the baboon a little to the right because symmetry is unattractive here.
3. Basic adjustments
Light
As you can see, the baboon — the subject of the photo — is underexposed while the sky looks okay, so we need to lift the shadows.
▷ In the Photoshop Layers panel bottom right, click on the half-coloured-in circle icon (as shown here) which shows the “Create new fill or adjustment layer” (remember this icon as you often use this), and choose Light.
▷ Move the Shadows slider right, to about +65.
Test the other sliders to see what happens, but in this case you do not need them.
Colour
Let’s tweak the colour temperature, to make the scene a little warmer.
▷ Make sure that the Background layer is selected in your Layers panel.
▷ Click on the Create new fill or adjustment layer icon as you did before, and choose Color and vibrance.
▷ Move the Temperature slider slightly to the right to about +7.
Test the other sliders to see what happens. Note that Vibrance means mid-tone saturation.
Clarity
Here, clarity means local contrast, and one often increases this slightly to have a, well, “more contrasted photograph.
▷ Again, make sure that the Background layer is selected in your Layers panel.
▷ Click on the Create new fill or adjustment layer icon, and choose Clarity and dehaze.
▷ Move the Clarity slider slightly to the right to maybe +15.
To review your handy work, turn the eye symbols off and on in the Layers panel.
Cropping and levelling, light, colour and clarity (all as explained above), are the most common basic and frequent manipulations you would make to a newly taken photograph.
When you are satisfied with the result, flatten the image (so that it is lighter, easier to export…)
▷ go .
4. Masking with Camera Raw Filter
The jury is still out whether the below, automatic masking, can be done better in the Photoshop Camera Raw filter, or in Photoshop proper. You will be learning a bit of both.
Selecting the sky and the subject
With the flattened baboon image still open in Photoshop, open the Camera Raw Filter: go , or press or ⇧⌘A.
Now the boundary between Photoshop editing for adjustments and for manipulation becomes blurred!
Click on the Masking symbol near the top right and have a general look.
As an example:
▷ Click on Select Sky for just the sky. Experiment. (Note that this automatic sky selection is pretty good but not perfect, but probably good enough for most uses.)
▷ Click on X to invert, for selecting everything except the sky.
▷ Now cancel this selection (click on three dots next to “Mask 1” and click “delete”)
▷ Now click on Select Subject: impressive, hair and all!
Experiment by moving some slider settings. When done you can click “OK” bottom right to commit your changes to the image.
Selecting features of a portrait
Now open “2_family-in-paris.jpg” in Photoshop.
Again, go , or ⇧⌘A, and the Camera RAW space opens.
Again, click on the Masking symbol near the top right but this time long-click (press) and a dropdown menu will appear. Choose Select People and after a few seconds Photoshop has recognised the four people as indicated by the four icons beneath “People”.
You are now going to apply some henna to the hair of the mother (make the hair redder)…
▷ Click on the “Person 1” icon (that’s the mother), and note that the mother is selected (in red), and note too that individual portrait features have been identified (Face Skin, Body Skin, Eyebrows…).
▷ Click on each portrait feature to select, then click to de-select — and satisfy yourself that Photoshop is indeed capable of selecting these.
▷ Select just the Hair and then click on Create. Note the many sliders that become available for just the hair.
▷ But Photoshop has selected also some of the girl’s hair below the mother: So click on Subtract then click on Brush and, make sure that the Flow and Density sliders are both at 100, brush out the girl’s hair — so that just the mother’s hair is selected.
▷ Open the Curve tab if not already open; select the red adjustment; drag the curve slightly upwards and the hair turns red. Further adjust the red-ness by slightly moving the Hue and the Saturation sliders above, until you are satisfied with the result.
▷ Note that had you not been satisfied with the selection, you could have clicked on Add or Subtract, but here the selection is fine.
Photo by Loly Galina on Unsplash
Other useful things you can do with these portrait features include
- Apply lipstick
- Whiten teeth by reducing Saturation, or adding more White, or increasing Exposure.
- Whiten the whites of the eyes (the “Eye Sclera”) using the same as you do for teeth.
- Modifying the colour of the eyes after selecting “Iris and Pupil”.
- Smoother facial skin, particularly with older people, by reducing the Clarity or the Texture.
Such modification should not be overdone — better to have a subtle effect.
Photoshop is using machine intelligence to make the selections as above, and it does not always get this right or accurate enough. Note that there are other ways to, for example, whiten teeth — then just google something like “how to whiten teeth in Photoshop”.
(New in Photophop 2025: a select people functionality with even more detail — see later.)
5. Detail menu
Noise reduction
Often photos are taken in low light hence have high ISO values and this introduces noise — graininess. First, you will apply noise reduction.
Open “3_shark.jpg” in Photoshop.
▷ Open the Camera Raw Filter by going , or ⇧⌘A.
▷ Open the Details panel.
▷ Zoom to 200% — the zoom value is the very small number very bottom-left.
▷ Hold the space-bar and drag the image so that the shark’s eye is approximately in the centre.
▷ Note that the image contains a lot of noise, so move the Noise Reduction slider maybe halfway across to about 50, and note that the noise has mostly disappeared.
Sharpening
▷ While looking at the eye, move the Sharpening slider to maybe 30.
▷ Change the zoom to “fit in view”, and note how the image has been improved.
▷ You might want to go to the Effects panel to further improve the image, for example by increasing Clarity maybe to +50. Try this!
▷ Click “OK” bottom right.
6. Spot removal
This photo was taken into a fish tank so there are a lot of spots, which you will now remove.
▷ Again Open the Camera Raw Filter by going , or ⇧⌘A.
▷ Click on the Remove tool on the right (eraser icon as shown here on the right).
▷ This opens the Remove panel offering three options as shown below: (1) Content Aware Remove (2) Heal and (3) Clone.
Content-Aware Removal automatically replaces the selected area with content that matches the surrounding area.
Heal blends the selected area with the surrounding pixels to create a seamless patch.
Clone duplicates the selected area and allows you to place it in a different location within the image.
Click on the Heal icon (the one in the middle).
▷ With the “Size” on 4, “Feather” say 20 and “Opacity” of 100, click on the photo’s spots and blemishes. If the blemish (spot) is oblong, you can drag instead of click.
▷ Select and unselect the options “Visualise Spots” to see what happens.
To change the tool size hold down the two keys ⌃⌥ (control+option) at the same time, then drag left-and-right to change the size and up-and-down to change the hardness. On an English QWERTY keyboard you can change the size simply by pressing the square brackets [ and ].
So remove some spots on the image by clicking or dragging on a spot — to satisfy yourself that you can do this. When done click “OK” bottom right.
Note that there are more (and more powerful) tools in the main Photoshop area for removing material from an image. More about this in the next Photoshop lesson.
7. Footnote:
Photoshop Camera Raw Filter vs the Lightroom Classic application
If all you are interested in is passing this course, then you do not need to read the rest of this page.
As explained (will be explained) in the Intro to Photography lesson, when you take a photo, the camera tries to guess how a human would perceive the electromagnetic light waves that hit the camera’s sensor, and then renders it for the user as a JPG or HEIF image — the result, so to speak. And then, crucially, the camera throws away all the original information. But “real photographers” shoot in camera RAW, and keep this initial information.
A RAW image— an unprocessed file containing all the data captured by a camera sensor — preserves maximum detail, dynamic range, and colour information, allowing extensive adjustments in editing without quality loss. RAW files are large and require dedicated software.
When you open a RAW image in Photoshop or when you open a JPG in the Photoshop Camer Raw Filter, you get essentially the same capabilities (and look) for photograph editing. You are using the same RAW engine.
The Adobe Lightroom Classic application is used by Photographers who shoot primarily in RAW, and has a workflow geared also towards organising and sharing photos, besides its editing capability which is essentially the same as the above. If you can edit in the Photoshop Camer Raw Filter you can edit in Lightroom Classic!
And then there’s Adobe Lightroom (not the same as Adobe Lightroom Classic). Lightroom functionality works pretty similar to the RAW stuff as explained above. It exists also as an app for mobile devices, which includes a Lightroom mobile camera app — so you can shoot RAW photos with Lightroom with your smartphone camera. The RAW photos then sync via the Creative Cloud with all your other Creative Cloud enabled devices. So cool!