We measure the zero point of the Stanek (1996) extinction map by comparing
the observed (V-K) colors of 206 K giant stars with their intrinsic (V-K)_0
colors as derived from their H\beta indices. We find that the zero point of the
Stanek map should be changed by \Delta A_V = -0.10 +/- 0.06 mag, obtaining as a
bonus a three-fold reduction of the previous statistical error. The most direct
way to test for systematic errors in this determination would be to conduct a
parallel measurement based on the (V-K) colors of RR Lyraes (type ab).Comment: 10 pages, 1 figur