[Like other recent posts, this is an updated repost of an older post from the previous Dejal blog; here’s the original in the web archive for comparison.]
I take a lot of screenshots while documenting my apps, and for my personal Sinclair Trails blog. While I’ve used third-party tools in the past, Apple’s built-in screenshot tools work really well.
The simplest is the whole-screen screenshot hotkey. Pressing ⇧⌘3 (Shift-Command-3) will save a PNG image of the whole screen (or multiple pictures if you have multiple screens) to the Desktop. (You can change the hotkey via the System Settings ▸ Keyboard ▸ Keyboard Shortcuts ▸ Screenshots options.)
Perhaps slightly less well known is ⌃⇧⌘3 (Control-Shift-Command-3), which saves the screenshot onto the Clipboard. Very handy for pasting into emails and such.
The one I find most useful is ⇧⌘4, though. This displays crosshairs with a coordinate display, and when you click-and-drag out a selection, the coordinates change to the selection size. Very handy. This saves the selected area to a PNG file.
Similarly, ⌃⇧⌘4 saves a selected region to the Clipboard.
These selection screenshot options are even more flexible than that, though. After invoking them, but before dragging a selection, you can press the Spacebar to highlight the window under the crosshairs. Clicking will then take a shot of that window, including the border.
While dragging a selection, there are more options. You can hold the ⇧ (Shift) key to constrain one axis — to keep the height the same while adjusting the width, or vice versa.
You can also hold the ⌥ (Option) key to adjust the size around the center point, instead of from the point where you started dragging.
And you can hold the Spacebar in selection mode to reposition the whole selection, keeping the size the same. Very handy.
And you can cancel the screenshot simply by pressing Escape. This can be useful on occasions other than just changing your mind: you can use the screenshot tool as a ruler, measuring the number of pixels of an object by dragging out a selection and reading the size display from the crosshairs, then hit Escape to exit without taking a shot.
Finally, ⌃⇧⌘5 presents an interactive panel that lets you choose between capturing the whole screen, a window, or a selection, or even recording the contents of a window or selection to a video, plus options of where to save it, a delay timer, and more.
Very useful. If anyone knows of any other tricks with the screenshot tools, please let me know!