Fionnuala Draper makes soy candles and sells them through her own website. Her daytime product photos were technically fine but looked identical to every other candle brand. She started experimenting with night photography after noticing that lit candles photograph differently in low ambient light.
The specific setup
She placed a lit candle on a dark wooden board, positioned near a window at 9 pm. The only light source was the candle itself plus faint street light from outside. She used her phone in pro mode, setting the shutter to 1/15 second and ISO to 800.
Why the candle-as-light-source works
When the candle is the primary light, the flame becomes the focal point and the product glows from within. This is difficult to replicate in daylight or with artificial studio lighting without significant post-processing.
Fionnuala ran two versions of the same product listing, one with her original daylight photo and one with a night shot. After six weeks, the listing with the night photo had a noticeably higher click-through rate, though she notes the product description was also slightly different, so the comparison was not controlled.
The process took some trial and error with shutter speed. Anything slower than 1/10 second introduced motion blur from the flame.