Low surface brightness galaxies in different environments

We present the results of a recent survey aimed at detecting and estimating the number density of low surface brightness galaxies (LSBGs) in the field. With a sample of 520 LSBGs over 1.2 square degrees, these galaxies are found to dominate numerically over higher surface brightness, "normal" galaxies by an order of magnitude. We have also analysed their photometric properties, finding steep-rising distributions towards faint central surface brightnesses and small exponential scale-lengths. We also discuss an ongoing wide field survey for LSBGs in the Virgo cluster, making use of the highly efficient Tech Pan films on the UK Schmidt Telescope. Preliminary results have confirmed the usefulness of these films for faint galaxy photometry, enabling the detection of large numbers of LSBGs in a region of parameter space previously inaccessible to large-scale surveys.