Index (this will be updated as the series unfolds)
Part 1a: Importing Files and File Types
Part 1b: Camera Raw
Part 2: Colour:
Part 3a: The Workspace
Part 3b: Example Layers Workflow
Part 3c: Adjustment Layers
Part 4: Grouping, Masks & History
Part 5: Selection & Paths (Pen Tool)
Part 5b: Healing Brush, Patch or Clone Stamp Tool?
Part 6: Image Size and Interpolation
Canvas Size
Resizing
Free Transform
Part 7: Smart Filters & Sharpening
Cropping:
Photoshop retains those age-old terms associated with traditional photography. A 'crop' is quite simply the process of removing portions of an image to create a new composition. The Crop (C) tool in Photoshop is really easy to use.
Click the mouse over the image where you wish to begin the crop, then hold and drag in the vertical and horizontal directions as you please. If this is a rough selection, then it's possible to adjust any left-right or up-down selection individually. To constrain proportions, hold down the Shift key whilst making adjustments with your mouse.
Caption: Example crop process
Canvas Size (trim)
It is also possible to trim an image by adjusting the Canvas Size. The Canvas is the physical size of your frame - so by making that frame bigger or smaller there will be no effect on the contents layers, just the capacity of that frame will become physically larger.
Image >
Canvas Size (Alt+Ctrl+C)
The control window allows you to see both the physical (pixel) size of the file, as well as the file size (kbs). Adjusting the physical size will change the file size accordingly and there's plenty of options to choose from to measure - cms, mms and pixels are likely to be the most useful. Clicking the 'relative' box will constrain the proportion ratio of up-down to left-right adjustments (or vice versa). Standard adjustments are calculated from the centre of the image, but it is also possible to control the direction of the canvas extension. Those arrows in the middle, click on one and it vanishes. This means that the extension will therefore no longer expand in this direction - ideal to save moving any layers around to the edges! Lastly, the 'Canvas extension color' controls what colour the canvas will take on should you be making the canvas larger ('Background colour' refers to the colour selected in your colour palette).
Resizing
If you're in need of resizing your image - and by this we mean make it smaller - then Photoshop can do this with ease. However, there's a whole can of worms opened upon resizing - you will need to read on to gather an understanding of image interpolation, loss of detail and therefore a need to use a Sharpening filter. But enough about that for now, and on with the simple - well, simpler - bit!
Image >
Image Size (Alt+Ctrl+I) will get you to the image size interface.
Here it's possible to change your image size - we're concerned here with making your image smaller, as upscaling is a rule breaker that we'll come to later.
There's two things to think about with resizing:
1. Changing physical size (pixels). Simply change your width and/or height values as you wish them to be. To maintain image proportions click the “Constrain Proportions” box so that adjusting one value will keep the image size relative.
2. Changing the resolution. This essentially alters not just the resolution itself but also physical size (pixels) of the image. By lowering the resolution you are, as such, asking Photoshop to remove available information from the file. So the physical size adjusts accordingly in order to attempt to preserve detail - only at a different scale.
Sounds confusing? It's not really - both are, in essence, one and the same. Imagine that you have two of the same images. The first is 1000pixels wide at 300dpi, the other is 2000pixels wide at 150dpi. Both images contain the same amount of data/detail (as 1000x300 is the same as 2000x150).
Try it for yourself, make a new file in Photoshop - say 1000x1000pixels at 300dpi. Then go to change the image size, adjust the resolution box to 150dpi (for example) and the physical size of your file will now measure 500x500pixels.
Free Transform
It is possible to adjust the orientation of an image, a specific selection or an individual layer. If something's not quite straight enough then you can set this right, if you need to rotate a layer by a fraction so it's where you want it to be, then Transform is the way to go - this can be found in many guises however…
Your basic set of layer adjustment options lies under Edit > Transform > where there are a set of options (Rotate 180°, 90° Clockwise and so on) that apply only to the selected layer.
For a transform that applies to all the image and its layers there's a slightly different route - Image > Rotate Canvas.
More seasoned adjustments come in the form of Edit > Free Transform (Ctrl+T) - allowing for arbitrary rotations, distortion and resizing.
Caption: A selection is made on the left eye selection, and free transform applied. The outer box begins 'flat', so any rotational adjustments can physically seen. Within the Free Transform box, as there is nothing surrounding the eye area on this layer, auto selection occurs to represent what it is undergoing transformation.
Rolling the cursor over the corners of the Free Transform box changes the cursor to enable arbitrary rotation - simply click and mouse and drag through to the desired angle. The rotation is based upon a central pivot (see centre of Free Transform box) that can be moved to anywhere within the whole image to act as the central pivot point. This will adjust the way in which rotation occurs in relation to this point - useful if there's a specific reference point within the image that your selection needs to rotate around.
Caption: Before and after free transform of left and right eyes. The horizontal and vertical lines have been added to show the subtle difference of the levels of one eye against the next and how before and after have been physically moved for a slightly different spacing.
It's important to realise that you are not limited to the way in which you can adjust the content within any given image or layer. Picking up from an earlier layers tutorial, the transform function adds an essential new level to the process of retouching and Photoshop as a whole.
