Elves are donut-shaped optical emissions, which occur at altitudes of 70-95 km above energetic cloud-to-ground (CG) discharges or intracloud (IC) discharges. Elves are believed to be the emission associated with the heating of the molecular nitrogen and oxygen by energized electrons. Free electrons are accelerated by the electromagnetic pulses emitted by CG or IC discharges. The left panel shows the video image (60 frames per second) taken by Watec 902b CCD with a 12 mm surveillance camera at UT13:07:25 on June 22, 2020. The right panel shows the image sequence taken by Phantom high-speed camera (10,000 fps) + Sigma 20 mm F1.4 lens with image intensifier aid, which approximately equals the dashed line rectangle. The total emission is about 200 us. The horizontal size of the elves is about 200 km, with a hole diameter of 80 km. All of the original images are recorded by black/white cameras and enhanced by Matlab hot colormap.  The observation site is at the Yushan weather station (Lat/Long: 23.47° N 120.95° E, elevation 3845m) and is also at the north peak of Mt. Yushan, which is the highest mountain in Taiwan at 3,952 m (12,966 ft) above sea level, giving Taiwan the 4th-highest maximum elevation of any island in the world.  From NCU SOL https://sites.google.com/g.ncu.edu.tw/ncu-sol/