Zooming Instructions.
Using a mouse:

Click anywhere on the image to zoom in. Hold the mouse button down and drag to move around the image, or click the control buttons at the bottom
of the image window to zoom in, zoom out or pan around, or reset to the default view.

You can use the navigator in the top left corner to move around the image once zoomed in - just click inside the highlighted area and drag with your
mouse to the section you'd like to view.

Alternative keyboard shortcuts:

Zoom in = Shift key
Zoom out = CTRL key
Pan left = left arrow key
Pan right = right arrow key
Pan up = up arrow key
Pan down = down arrow key
Reset = ESC key