  Multifocus microscopy enables recording of entire volumes in a single camera
exposure. In dense samples, multifocus microscopy is severely hampered by
background haze. Here, we introduce a scalable multifocus method that
incorporates optical sectioning and offers axial superresolution capabilities.
In our method, a dithered oblique light-sheet scans the sample volume during a
single exposure, while generated fluorescence is linearised onto the camera
with a multifocus optical element. A synchronised rolling shutter readout
realised optical sectioning. We describe the technique theoretically and verify
its optical sectioning and superresolution capabilities. We demonstrate a
prototype system with a multifocus beam splitter cascade and record monolayers
of endothelial cells at 35 volumes per second. We furthermore image uncleared
engineered human heart tissue and visualise the distribution of mitochondria at
axial superresolution. Our method manages to capture sub-diffraction sized
mitochondria-derived vesicles up to 30 um deep into the tissue.
