I decided to have a little fun one day. I took a few test shots to get the correct settings and exposure. I checked the histogram and after adjusting exposure, ended up with the following settings.

I put my Nikon D200 on a tripod with a 17-55mm lens.  I set the lens to a 5 second shutter and f22 aperture. I used Auto-ISO which set the ISO to 125.  One mistake I made was using Auto-white-balance.  I should have set this so it was consistent over all my shots.

I then set the self timer on, and shot a dozen or more shots, while I moved into various positions.  On the D200, I can use the Interval timer so it just snaps them every minute (or every 5 minutes or every 30 minutes).

I then loaded the JPG files into Photoshop and combined them (each on their own layer) into one image.  To do this, choose your "bottom image", and then open the second picture. Now "shift" and drag that image thumbnail into the first image.  Close the second image.   Repeat for all images.

Now for each image, use a layer mask to remove everything buy you.  The great news:  you don't have to be exact, since the surroundings are "all" the same.  You can be a little sloppy (although I was a little too sloppy).

My daugher simply said:   Dad - that's just plain scary!

My next attempt will add some fun:  I'll change clothes and looks in each position.  Maybe even throw a ball between my selves :)

Hope you enjoyed.