0, 1, 2, 4 will zoom the proof (fit, 100%, 200%, 400%) – up and down arrow keys to move through the zoom positions, shift + up and shift + down will nudge the zoom by 5%.

z + scroll will zoom between these zoom states.

r will rotate the proof clockwise (shift + r rotates the proof counter-clockwise).

For those on mobile devices and tablets, pinch to zoom.

To zoom in to a particular area of the proof, place the mouse pointer on the area and use the scroll wheel to zoom in/out. Or, use the marquee zoom tool.

You can type a zoom percentage to jump to – up to 1000%.