How to Change Screen Capture Formats — Last week, when talking about the new version of Snapz Pro X in TidBITS, I mentioned that Tiger changes the default file format used for screen captures taken with Command-Shift-3/4 from PDF to PNG. Thanks to Paul Schreiber for alerting me to the fact that you can change that default format back to PDF or to another format, presumably as long as it’s one supported by QuickTime, such as JPG (extra points for anyone who wants to figure out all the possibilities and send me a list). Follow the steps below to make Tiger save screenshots as PDF.
Copy the "defaults write" line below, paste it into the Terminal window, and press Return.
defaults write com.apple.screencapture type pdf
Log out or restart your Mac to make it pick up the new setting.
If you wish to reset the file format back to PNG, just repeat the steps, replacing "pdf" in the "defaults write" line with "png". [ACE]