  Halide perovskites have remarkable properties for relatively crudely
processed semiconductors, including large optical absorption coefficients and
long charge carrier lifetimes. Thanks to such properties, these materials are
now competing with established technologies for use in cost-effective and
efficient light harvesting and light emitting devices. Nevertheless, our
fundamental understanding of the behaviour of charge carriers in these
materials particularly on the nano to micro scale has on the whole lagged
behind the empirical device performances. Such understanding is essential to
control charge carriers, exploit new device structures, and push devices to
their performance limits. Among other tools, optical microscopy and
spectroscopic techniques have revealed rich information about charge carrier
recombination and transport on important length scales. In this Progress
Report, we detail the contribution of time-resolved optical microscopy
techniques to our collective understanding of the photophysics of these
materials. We discuss ongoing technical developments in the field that are
overcoming traditional experimental limitations in order to visualise transport
properties over multiple time and length scales. Finally, we propose strategies
to combine optical microscopy with complementary techniques in order to obtain
a holistic picture of local carrier photophysics in state of the art perovskite
devices.
