Much more info about zooming in Quick Look!
I posted a tip last week about how it is possible to zoom in Quick Look using "Option - Click" and unzoom with "Shift - Option - Click". It didn't work for a lot of people. I finally figured out why and I also found another way that is even faster. So the shortcut "Option - Click" only works with images such as Jpeg, Tif, etc. The even faster way of zooming in on images is to hold down Option and scroll with your scroll mouse. If you want to zoom in on a PDF, the shortcut is different. It is "Command +" to zoom and "Command -" to unzoom (it is most likely different depending on the keyboard layout you use). I really don't understand why Apple didn't choose a standard way of zooming in Quick Look no matter what you are looking at, but that's the way it is.