Command+Shift+3 – Take a screenshot of the entire screen.
Command+Shift+4 – Take a screenshot of an area
Command+Shift+4 then hit Spacebar – Takes a screenshot of a window (this is the one I use all the time)
Command+Control+Shift+3 or Command+Control+Shift+4 – Takes the screenshot and store it on the clipboard.
I use a program named Sharpshooter which lets me automatically rename them, choose where to save them.
OS X can make screenshots in any of these formats: BMP, GIF, JPG, JP2, PSD, SGI, TGA, PDF, PICT, PNG, or TIFF.
99% of the people who will ever read this should use JPG.
I’ve been using PNG because I thought they were smaller than JPGs (nerd note: which is true for PNG8, but not for PNG24).
To change this, use the Terminal.app and copy/paste this:
defaults write com.apple.screencapture type jpg
(you can replace “jpg” with any of the above options, just remember to use all lowercase, and no “.” — use “jpg” not “.jpg”). Then copy/paste this:
killall SystemUIServer
which will confirm the new setting without requiring you to logout or reboot.
