Viewing Files with the Quick Look Window in Mac OS X Lion
The Quick Look command in Mac OS X Lion displays the contents of the selected file in a floating window without launching an application. This Mac OS X Lion feature can be handy if you want to peek at the contents of a file before you open it to make sure that you have the right one. Simply select the file and then choose File→Quick Look, press Command+Y, or (easiest of all) merely press the spacebar.
The bad news is that while Quick Look works with many types of files, it doesn’t work with all files. You’ll know it didn’t work if Quick Look shows you a big document icon instead of the contents of that file.
For the file to fill the entire screen (Slideshow mode), do any of the following:
Hold down Option, and choose File→Slideshow.
If your file is already open in the Quick Look window, click the double-diagonal-arrow button at the bottom of the window.
In Slideshow (full-screen) mode, press Esc to return to the Quick Look window.
If you select multiple items before you invoke Quick Look, a pair of slideshow icons appears at the top of the Quick Look window so that you can view all the selected items at the same time as index sheets.
When you’re finished with Quick Look window, click the X button in the top-left corner; if you’re in full screen mode, click the X button in the slide show control bar; or press Command+Y, which works in either mode.