How do I zoom into a section from fullscreen and then zoom back out to full screen. I can zoom in OK but can't work out what to do to zoom back out smoothly. The problem seems to be the start point of the outward zoom - how do I get the section size and position the same as the end point of the inward zoom and still be able to get back to full screen?  I know I am being stupid but I find all the zooming instructions very confusing.  Many thanks for unconfusing me!