Yes it is - after the monitor is nothing more than a high class tv screen.
You will need to set the shutter speed by trial and error though.
Jim

Read your camera manual. Some can and some can't.

This is possible, but few consumer cameras can do this.
I don't know what kind of camera you have and if your manual or brochure
does not mention that you can do this, then there is nothing you can do.
An example is Minolta A1 or A2. Here you need to purchase special software
for the camera and then you can control the camera from your computer (you
can actually control every function and even set the camera to take pictures
at specific time intervals, etc) and see how the picture will look like on
your computer screen as you change variables such as aperture, contrast,
etc., but don't expect to see the picture full screen. You get about 1/4 of
your screen.
I think the Minolta A1 and A2 are the lowest price cameras available to do
this.

Using XP, connect your camera, goto My Computer. Your camera should be there
if it's a newer model. One of the options under "Camera Tasks" is "take New
Picture".
If that doesn't work, there is a free program (cPix.exe) that allows
controls of most cameras