This video was captured during an in-situ heating stage SEM experiment using a secondary electron camera at the University of Manchester, UK. The Ti-6Al-4V sample was heated to 1000°C to the full β-phase field and then slowly cooled (0.3°C/s) through the β transus, and the α-phase nucleation was recorded by the contrast change in the secondary electron camera from topography development on the sample surface due to surface relief. Microscope operated by Dr Alec E Davis and Dr Jack Donoghue, sample preparation by Nick Byres. These results were published in an Acta Materialia paper in 2021: Acta Materialia paper: https://doi.org/10.1016/j.actamat.2021.117315 Researchgate (free peer reviewed preprint): https://bit.ly/3EHs7Na