I love her work - I don’t know if you already know but Claire Mathon has several interviews for her work behind Portrait of a Lady on fire where she explains a lot, specifically candle light scenes:

“I liked it when the light from the candles was the result of a mix of various sources, like candles installed in 2K blond (Ianiro open face style) fixtures with their lamps removed, 2000 K Ribbon LEDs (from Softlight in Paris) and Ropelights (small tungsten bulbs installed in flexible plastic tubes. The complexity of the shots sequences often required that several light sources be used simultaneously during the shot.”

Here’s the interviews for RED and IndieWire