  We estimate the benefit of muon colliders for photon physics. We calculate
the rate at which photons are emitted from muon beams in different production
mechanisms. Bremsstrahlung is reduced, beamstrahlung disappears, and laser
backscattering suffers from a bad conversion of the incoming to the outgoing
photon beam in addition to requiring very short wavelengths. As a consequence,
the cross sections for jet photoproduction in $\mu p$ and $\mu^+\mu^-$
collisions are reduced by factors of 2.2 and 5 compared to $ep$ and $e^+e^-$
machines. However, the cross sections remain sizable and measurable giving
access to the photon and proton parton densities down to $x$ values of
$10^{-3}$ to $10^{-4}$.
