I want to know the answer to the following question:
What did the muzzle flashes of the firearms used by the infantry reveal?
All the background I'm provided with is that "Adaptations of the standard autocannon, originally intended for air-to-ground use, and heavier artillery systems were commonly used for most anti-aircraft gunnery, starting with standard pieces on new mountings, and evolving to specially designed guns with much higher performance prior to World War II.". Is that enough to answer the question?