Exact results for the magnification and effective focal length of a mu
ltiple-path telescope are presented. We present analytical results for
the third-order design of this system, using the Seidel sums for the
five aberration terms. Numerical calculations are used throughout to c
orroborate these results. Third-order aberrations remain small or at l
east stable as the number of paths is increased. (C) 1997 Optical Soci
ety of America.