Lighting logic describes whether or not the lighting in a scene makes sense. Considering that film making is in a lot of cases a big illusion there is not really a distinct line of what makes sense and what doesn’t. Its is more a question to disobey certain limitations e.g. sunrise is always in the east, under normal circumstances no thick smoke in a submarine and so on to achieve better lighting. Like shown in the examples below.
This opening scene from ‘The da vinci code’ which plays in the grand gallery at the Louvre is a good example for ignoring logic to achieve better lighting. There are a couple of things that don’t make sense or wouldn’t happen in real world.
Moon light creating large patches of light on the floor wouldn’t be possible in the grand gallery, there is no natural light coming in from the outside.
The practical lights stepping from the foreground to the background on the left and right wall doing a great job in creating depth. This kind of lights can’t be found in the real world grand gallery nor would it make much sense in any other museum.
Considering its a crime scene you would expect it to be brightly lit. Which obviously would make everything dull and anything but mysterious.
Even though all of the above described clearly doesn’t make sense the scene itself is believable.
extensive use of smoke throughout the movie to add more depth
extensive use of smoke throughout the movie to add more depth
‘Das Boot’ is another great example in which logic was ignored in favor of better lighting. In a lot of interior shots thick smoke was used to give the confined space of the submarine more depth and create separation between foreground and background. Looking at it from a pure logic point of view it doesn’t make sense to have such thick smoke come from anywhere within the submarine not even the engine room.
Both examples showcase that you can basically turn real world logic upside down as long as its done believable no one will question it.
