  We show how and why the small distance ("hard") interaction, calculable in
perturbative QCD, provides a mass cutoff in Gribov's formula for photon-proton
collisions. This enables us to find a new and more restrictive bound for this
process, $\sigma(\gamma^{*}p)\leq C(ln 1/x)^{5/2}$.A simple model the published
experimental data over a wide range of photon virtualities ($Q^2$) and energies
($W$), is developed. This model provides a quantitative way of evaluating the
relative rate of the small and large distance contributions, in the different
kinematic regions. The main results of the analysis are (i) that even at $Q^2
=0$ and high energies the short distance contribution is not small, and it
provides a possible explanation for the experimental rise of the
photoproduction cross section; and (ii) at large values of $Q^2$, the long
distance processes still contribute to the total cross section.
