We suggest a method to determine ${V}_{\mathrm{ub}}{/V}_{\mathrm{ts}}$ through a comparison of $\stackrel{\ensuremath{\rightarrow}}{B}{X}_{u}l{\overline{\ensuremath{\nu}}}_{l}$ and $\stackrel{\ensuremath{\rightarrow}}{B}{X}_{s}\ensuremath{\gamma}.$ The relevant quantity is the spectrum of the light-cone component of the final state hadronic momentum, which in $\stackrel{\ensuremath{\rightarrow}}{B}{X}_{s}\ensuremath{\gamma}$ is the photon energy while in $\stackrel{\ensuremath{\rightarrow}}{B}{X}_{u}l{\overline{\ensuremath{\nu}}}_{l}$ this requires a measurement of both hadronic energy and hadronic invariant mass. The non-perturbative contributions at the tree level to these distributions are identical and may be canceled by taking the ratio of the spectra. Radiative corrections to this comparison are discussed to order ${\ensuremath{\alpha}}_{s}$ and are combined with the non-perturbative contributions.