Retinal plays a key role in visual perception. In the ground state it occurs in the cis form with a bent side chain, whilst after light exposure it assumes the trans form with the methyl groups on one side and the side chain straight. Laboratory X-ray data collections are a bit challenging due to radiation damage. More than half of the atoms are hydrogen. We have established a protocol to load samples cold into the top loading CCR and found that crystals remain stable under He atmosphere at room temperature. This opens the possibility to do a multi temperature data collection using neutrons and study the protons in both forms. We plan to collect data at 4.5K, 50K, 100K, 200K and 300K and then monitor the cis to trans transformation at 100K under light exposure on the beamline. We ask for 6 days of beamtime on SXD equipped with a top-loading CCR. Light exposure will be done using diodes.