Who photographed aircraft formations in flight

Were wartime photographs of aircraft in flight normally taken by photo-reconnaissance aircraft or by another crew?

Usually another aircraft in the formation took them, though photo-reconnaissance aircraft were also used.

Many wartime photographs of aircraft in flight were taken from another aircraft flying with the formation. Dedicated photo-reconnaissance aircraft could also produce such images. A dramatic aerial view therefore does not automatically identify the photographer's aircraft or mission. That uncertainty is worth remembering when interpreting captioned wartime aviation photographs.