Reduce Preview's PDF zoom after Spotlight
When you click on the PDF in the Spotlight results, it opens up in Preview with the search term highlighted throughout the document. This is pretty useful, however the PDF is actually zoomed in 280 percent. This means you can read the word you searched for pretty easily, but you can't see anything else.
Luckily, by changing one line in the Preview preferences, you can change the zoom level to something less extreme. The easiest way to do this is using the Terminal.
First, quit Preview if it is running and open up Terminal from the Utilities folder in the Applications folder. Type the following line and press return:
defaults write com.apple.Preview Preview -dict-add PVPDFSpotlightSelectionSize 10
The 10 at the end corresponds to a 100% zoom level. By default, this number is set to 28, or 280% zoom. If you want some zoom, but not quite as much, try a number like 15 for 150% zoom.
If you don't want to use the Terminal, or you are curious to see what the command actually does, you can open up the preference file in Property List Editor (which you will only have if you have installed the Developer Tools from the Mac OS X install Disk). Go to your user folder and navigate to Library/Preferences and open up com.apple.Preview.plist using Property List Editor.
Use the expansion Triangles to navigate to Root/Preview/PVPDFSpotlightSelectionSize. Here you can see the number is 28 (or 10 if you have already changed it in the Terminal).