BASIC
CAMERA SETTINGS - Method One
There
are two ways to use high-Speed Crop Mode effectively. My favorite
way is to simply set up one of the D2x's four Shooting
Banks as a special cropped shooting mode, and switching
to that mode when I need the cropped 2x capability.
The
second method involves setting Custom Setting f4 so that the
FUNC button on the front of the D2x turns crop mode on. It's
not my favorite way to set HS Crop, because I like to use
the FUNC button for Spot Metering instead. But, I shoot a
lot of nature stuff, where others don't. I'd say the second
method is the most popular, so we'll look at it first.
Look
at the pictures above for a sequence of screens to set the
FUNC button:

Once
you have Custom Setting f4 set to High-Speed Crop, you can
then use the FUNC button and Main Command-Dial (rear) to turn
crop mode on and off.

Simply
hold in the FUNC Button and rotate the command dial one click
in either direction. (see pages 4 and 205 in your manual)
You'll see a little rectangle start flashing in the bottom
left hand side of your camera eyepiece viewfinder, and some
tiny brackets will appear in the tiny rectangle on left bottom
side of the Top Control Panel LCD. See picture below:

Other
than these small changes, the only way you'll be able to tell
that you are in cropped mode is that the four corners of the
crop rectangle in the viewfinder will light up at the same
time the selected focus indicator does. I'm sure it will be
easy to forget that the camera is in crop mode, so pay attention
once you've selected it. (See pages 41 and 42 of your D2x
manual for details)
Remember
that the FUNC button/Command-Dial toggles the High-Speed Cropped
Mode on and off. Learn to recognize when your camera is in
cropped mode, and when it is not, if you are using this method.