Rigorous record-keeping and quality control are required to ensure the quality, reproducibility and value of imaging data. The 4DN Initiative and BINA here propose light Microscopy Metadata Specifications that extend the OME Data Model, scale with experimental intent and complexity, and make it possible for scientists to create comprehensive records of imaging experiments.@en

In the version of this article initially published, the affiliation for author Roland Nitschke was incorrectly formulated. The affiliation has been corrected to read “Life Imaging Center and Signalling Research Centres CIBSS and BIOSS, University of Freiburg, Freiburg, Germany” in the online version of the article.@en

In article number 1700323, a sparsity‐inducing scheme based on widefield stimulated emission depletion, which requires stringent control of the polarization state of both the excitation and depletion laser, is introduced by Bernd Rieger and co‐workers for superresolution fluorescence microscopy. The ideal state involves excitation and depletion lasers with linear polarizations, orthogonally oriented in the sample plane. This state is obtained from linearly polarized light from the laser, which is made elliptically polarized before reflecting off the dichroic mirror. @en

Light microscopy, allowing sub-diffraction-limited resolution, has been among the fastest developing techniques at the interface of biology, chemistry, and physics. Intriguingly no theoretical limit exists on how far the underlying measurement uncertainty can be lowered. In particular data fusion of large amounts of images can reduce the measurement error to match the reso-lution of structural methods like cryo-electron microscopy. Fluorescence, although reliant on a reporter molecule and therefore not the first choice to obtain ultraresolution structures, brings highly specific labeling of molecules in a large assembly to the table and inherently allows the detection of multiple colors, which enables the interrogation of multiple molecular species at the same time in the same sample. Here, the problems to be solved in the coming years, with the aim of higher resolution, are discussed, and what polarization depletion of fluorescence at cryogenic temperatures can contribute for fluorescence imaging of biological samples, like whole cells, is described.@en