Beigou Palace Museum Ventilator November 22, 2020 / Featured in Beigou Forbidden City Vault 北溝故宮文物典藏山洞 ↩ Image Metadata Credit Alexander Synaptic Date Captured March 15, 2017 Camera Nikon D3100 Aperture ƒ/7.1 Shutter Speed 1/60 sec Focal Length 18 mm ISO 3200 Exposure 0 EV Source Files 900 × 900 / 675 × 675