  Within the light front framework, we calculate the form factors for
$B\to\gamma$ transitions directly in the entire physical range of momentum
transfer. Using these form factors, we study the radiative decays of $B\to
l\nu_l\gamma$ and $B_{s(d)}\to\nu\bar{\nu}\gamma$. We show that the decay rates
of $B\to l\nu_l\gamma (l=e,\mu)$ and $B\to\nu\bar{\nu}\gamma$ are larger than
that of the corresponding purely leptonic modes. Explicitly, in the standard
model, we find that the branching ratios of $B\to \mu\nu_{\mu}\gamma$ and
$B_s\to\nu\bar{\nu}\gamma$ are $3.7\times 10^{-6}$ and $5.0\times 10^{-8}$, in
contrast with $3\times 10^{-7}$ and 0 for $B\to\mu\nu_{\mu}$ and
$B\to\nu\bar{\nu}$, respectively.
