Using the Mac
OS Native Screen Capture Ability
-Dave
Melvin
In preparing for podcasts & teaching classes, such as Mac
forensics, I do a lot of screenshots. While I have Snap Pro
Z, I tend to use the native Mac OS screen capture ability.
The Mac allows you to capture the entire desktop, an open
window, or a specific, designated area.
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When you take a screenshot, the images are saved to the
desktop as PNG files. Now, in Leopard and prior versions of
the OS, each PNG used the naming convention of “Picture” .
Any additional screenshots will be given a number in
sequential order (i.e. Picture 1, Picture 2, etc).
With Snow Leopard, this changes for the better, at least I
think so! The naming conventions that is used in SL is
“Screenshot” and the date/time group of when it was taken.
This makes it easy to segregate images and not have to worry
about having four Picture 3.png files, making you search for
the one you wanted.
Snow Leopard Sample Screen Capture - New Naming
Convention
Leopard Sample Screen Capture - Original Naming
Conventiion
Now, I can take a ton of screenshots while preparing for a
class. This really clutters up my desktop. After getting
tired of this, I decided to change the location of where my
screenshot would be saved. It is fairly simple to do this
using the Terminal.
First, create a folder on where you want to save your
screenshots. For ease, I created a “screenshot” folder on my
desktop.
Open up the Terminal, and type the following command:
defaults
write com.apple.screencapture location

Terminal
- Command line to change default Screen Capture
location
Remember, all you have to do to populate the folder location
in the command is to Drag the folder and drop it on the
Terminal. Once you have the command typed, hit the return
key.
Then type the command:
killall SystemUIServer

Terminal
- Command line to restart to user interface, force changes to
take effect
Once you click on the return key, this will kill and restart
the service and the new location will be set. Test it to make
sure that it worked!

Finder
Window - Showing new default location for Screen
Captures
The following are the screenshot key sequences:
- Command-Shift-3: Take a screenshot of the entire
desktop
- Command-Shift-4: Allows the selection of a specific
area
- Command-Shift-4-Spacebar: Allows the taking of a
screenshot of a selected window
- Command-Control-Shift-3: Take a screenshot of the
screen, and save it to the clipboard
Using the Control key in conjunction with with the above
commands will copy the screenshot to the clipboard, it than
can be pasted to wherever you would like.
You can also use the application, Grab, which is located in
the Utilities folder. Grab takes screen shots using a few
different key strokes to include a timed shot. Grab also
allows you to save the screenshot with any name you would
like. The file is saved as a TIFF.
You can
change this by exercising the same Terminal line command
techniques as above with the following syntax:
- defaults write com.apple.screencapture type png
- defaults write com.apple.screencapture type pdf
- defaults write com.apple.screencapture type jpg
- defaults write com.apple.screencapture type tif
- defaults write com.apple.screencapture type psd
Be sure to follow the command with 'killall SystemUIServer'
to force the changes to take effect.