Make candle stacking for more light actually useful and realistic: the number of candles required for another square of radius increases quadratically instead of exponentially, so 1 candle gives radius 2, 4 give radius 3, 9 give radius 4, 16 give radius 5, etc.

Later extended into a more general idea allowing light sources of any type to stack: candles each give 5 lumens (because a single candle’s light reaches up to sqrt(5) squares from the center), lamps give 10 lumens, potions of oil 2, and the full Candelabrum gives 20. To compute your total light radius, add up all the lumens and take the square root. (Note that this exact formula might scale too fast: 4 candles equals the Candelabrum).