What effect does a person's distance from a mirror have on the minimum mirror length required to produce his or her complete image?
f=focal point
i=height of image
o=distance of object
1/f=1/i+1/o
f=i+o,
f/o=i
as the object's distance increase the image becomes smaller, as the objects distance decreases, the image becomes bigger.
I really haven't dealt with lenses and mirrors in a while, so I could be wrong.