In general small direct light sources that are bright compared to the surrounding area/light.
Small is relative to distance the sun is large but is a small light source because of the distance and intensely bright.
Store lights are another they are not generally small and at 5 feet over head would produce white light return but at 20+ feet and brighter than the surroundings produce fire.
i see fire when direct sunlight rays are shone onto my diamonds. such as by an open window or outside under some shelter whilst light rays shine on the diamond.
i see fire outside in ambient sunlight.
i see fire by fireside
i see fire by candlelight
i see fire under led light
i see fire in grocery store lighting
i see fire in incandescent lighting
i see fire by moonligt
its just such a pity that i can't seem to capture it with a camera
I think you wrote a poem!