We show data from the SCUBA2 camera on JCMT, of molecular clouds. We focus on starless cores within the clouds. We present data of the Taurus region and show how the environment is affecting some cores' appearance in this region. We compare the SCUBA2 data with Herschel data and discuss the sensitivity of SCUBA2 to surface brightness in the sub-millimetre. We show how this leads to its ability to pick out the densest cores at a given temperature. Hence SCUBA2 preferentially picks out gravitationally bound pre-stellar cores. We discuss the effects of the magnetic field, and how this lends support to a model for the formation and evolution of cores in filamentary molecular clouds.
