Try a sunrise excursion to beat the crowds, watch mild spill over the caldera

https://www.scribd.com/document/1037270800/Private-Santorini-Tours-Luxury-Itineraries-Sunset-Moments-and-Hotel-Pickup-Made-Easy-133618

Try a dawn travel to overcome the crowds, watch pale spill over the caldera, and capture serene streets prior to the island wakes up.