Figure 3

Standard widefield image (a) compared to Mesolens HiLo-processed optical section (b) of zebrafish stained with Acridine Orange. Insets (c–f) show zoomed-in regions of interest (1–4) where the widefield and HiLo image were merged together (top half was widefield, bottom half was HiLo image). Contrast improvement was evident across the whole image and regions of interest showed fine detail that was barely noticeable in the widefield image. Optical sectioning parameter σ was set to 2, corresponding to 8.7 ± 0.1 μm. With σ set to 1 there were too many artefacts. There was still a hint of inhomogeneous brightness with σ = 2 but not so severe that false detail emerged in the final image. Setting σ higher would have resulted in an unnecessarily thick section.