Leonardo painted in chiaroscuro
 

Leonardo had mastered, some say pioneered the technique of chiaroscuro as well as sfumato, which is similar though with the transitions being from color to color, instead of modelling a shape from light to dark.
Caravaggio simply reintroduced said technique about a hundred years later with a livelier sensibility.
Rembrandt, however, was a real master.
Not to mention contemporary painter Odd Nerdrum,
great painter also.

Interesting old thread. I thought I would revive it with a reference to one of my favorite films.

"The Duellists"

This was Ridley Scotts first feature film. The entire film looks like a series of paintings. IF you watch carefully, you will notice that the light always seems to come from one source, (Usually a window or fireplace.) This is not only correct for the period, (Napoleonic era) it also lends that "Painterly look".

Film is also worth a look since it is about the obligations of honor... a theme he revisited in GLADIATOR.