Nikon D5 100 SLR shooting at night. After turning on the flash, something as big as a halo appeared in the picture.

The overhead flash is basically coaxial with the lens. When dust flies in the air, the flash will illuminate the dust in front of the lens and produce a bright spot, which is also common in flash photography of small digital cameras. As the picture shows, the yellow land in northern Shaanxi is dusty when dancing yangko, and there are many colorful spots after flashing.