M.W., G.S. and J.-P.C. thank I. Schlichting, R. Shoeman, B. Doak and T. Barends for long-standing support, advice and collaboration related to all aspects of serial crystallography experiments. G.S. and M.L. are grateful to M. Cammarata for the invaluable long-term advice and collaboration and the helpful discussions on several aspects of the time-resolved X-ray solution scattering experiments. M.W. acknowledges a stimulating discussion with D. Le Bolloc’h on energy dissipation in photoreceptors. M.W., G.S. and R.R.-S. thank I. Schlichting and R. L. Shoeman and S. M. Kapetanaki for their time invested during the screening beamtimes at the LCLS (P240) and the EuXFEL (PCS proposal no. 3007), respectively. The study was supported by ANR grants to G.S. and M.L. (PhotoGene) and to M.W. (BioXFEL), by CNRS grants to G.S. (XFEL Instruments) and to M.W. (GoToXFEL), and a grant to M.W. by GRAL, a project of the University Grenoble Alpes graduate school (Ecoles Universitaires de Recherche) CBH-EUR-GS (ANR-17-EURE-0003). M.W. and T.T. acknowledge financial support from the Partenariat Hubert Curien Sakura program, jointly funded by the Ministère de l’Europe et des Affaires étrangères (MEAE) and the Ministère de l’Enseignement supérieur et de la Recherche (MESR) of France and the Japan Society for the Promotion of Science of Japan. R.M. was supported by a GRAL PhD grant to J.-P.C. We thank E. A. Andreeva for advice on viscous matrix preparation for microcrystal injection; the EPSRC for access to the National Research Facility for Electron Paramagnetic Resonance Spectroscopy (NS/A000055/1 and EP/W014521/1); and the SACLA and SwissFEL staff for assistance. Funding from an EPSRC International Centre-to-Centre grant no. EP/S030336/1 was awarded to D.J.H., D.L. and N.S.S. R.R.-S. acknowledges travel grants from the EMBO (scientific exchange grant number 9591) and the Université Grenoble Alpes for a 1-month stay at the SACLA (Research Support Program for Graduate Students). R.R.-S. and S.S. were supported by CEA CFR PhD grants to M.W. M.C.D.-M. was supported by a PhD grant from the Ecole Normale Supérieure Paris. XFEL experiments were carried out at BL2-EH3 of the SACLA with the approval of the Japan Synchrotron Radiation Research Institute (proposal no. 2022B8815), at the SwissMX instrument at the Cristallina experiment station of SwissFEL (proposal 20231018). This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 884104 (PSI-FELLOW-III-3i). The SwissFEL Cristallina experimental station at the Paul Scherrer Institut was realized with financial support from the Swiss National Science Foundation and the University of Zurich under project no. 206021_183330. We acknowledge the use of the Park Innovaare Cleanroom for Optics and innovation for the production of the MISP chips. The ESRF is acknowledged for providing beamtimes (LS-3091, BLC-14546, LS-3226, LS-3303 and LS-3364) at the ID09 beamline. We acknowledge the French Biology/Health Panel Review Committee for the provision of synchrotron radiation beamtime at the ESRF on beamline BM07-FIP2, supported by the French ANR PIA3 (France 2030) EquipEx+ project MAGNIFIX under grant agreement ANR-21-ESRE-0011. We acknowledge the ESRF for the provision of beamtime for crystal screening and data collection (MX2686, MX2498 and MX2398) on beamlines ID30A-1, ID30A-3, ID23-1 and ID23-2 and the macromolecular crystallography group members for excellent support. SSX experiments were carried out at the I24 beamline at the Diamond Light Source under proposal numbers MX24447 and MX31850. The PORTO laser at Diamond was funded by the EPSRC (EP/P001548/1). This work was partially carried out at the platforms of the Grenoble Instruct-ERIC Center (IBS and ISBG; UMS 3518 CNRS-CEA-UGA-EMBL) within the Grenoble Partnership for Structural Biology. Platform access was supported by FRISBI (ANR-10-INBS-05-02) and GRAL. The IBS acknowledges integration into the Interdisciplinary Research Institute of Grenoble (IRIG, CEA). M.J.M. and P.M.K. acknowledge the Cardinal Research Cluster at the University of Louisville for access to high-performance computing resources.