cast shadow of a candle

[Patrick1]

This is more physics & light-related than color theory, but it touches on a topic raised here a while back.

Someone posted a painting of a lighted candle illuminated by another light source in front of it such that the candle's shadow was cast on the wall behind. In the painting, even the shape of the flame itself was painted in as part of the cast shadow. So some people were asking: in real life, does a candle flame block light such that it can cast a shadow, or would the flame be invisible in the cast shadow? I tried this setup and easily found the answer. But I'd like to take bets first .

[Einion]

I've looked at the effect so it would be cheating for me to answer - I wouldn't be guessing

Einion

[Gigalot]

Candle flame is not transparent. It can absorb light to make a cast shadow. It contain very hot carbon particles which emit light but also this particles absorbs other light.

[Brayzen]

Part of what I love about being an "artist" - I can twist, defeat and just plain ignore the laws of physics ... just call me Merlin ...

[Patrick1]

The candle is a few inches in front of a white closet door, and the only light source (other than the flame) is a halogen work light pointed directly at it.

And the answer is ...

There is a barely-visible (refractive/mirage-like?) impression of part of the flame visible at times in the shadow, but other than that, the candle's shadow looks the same whether it's lit or not.

[amandadun]

Huh, I never knew that. I guess I'm not very observant.


Cheers - Amanda

[Patrick1]

I didn't know for sure either until I tried it. Kinda neat...the disappearing flame.

[ebaytoad]

cast shadow of the smoke from the flame, as it is when a breeze blows it...sounds good....HI !! I'm old but new here...lol
Cindy

[Basalt]

Funny I saw this photo, I was studying for a test on lighting at the same time.
Some facts about light intensity for the nerds out there-


If the candle was 1 foot (12 inches) from the wall, the brightness (or 'Illuminance') is said to be 1 foot candle. The light coming from 1 candle is 1 candle power
What's interesting is what happens when the candle moves away from the wall. The intensity of the light decreases by 1/4 for each doubling of distance, so say the intensity level is 100% at 1 foot away, it is 25% at 2 feet away, and 11% at 3 feet away....
Light intensity = light output at source/(distance x distance)