Devin Korwin: Exposure in painting (Twitter Transcript)

Devin Korwin: "Is this Joaquin Sorolla painting exposed for the light or for the shadow?"

Concept Artist Devin Korwin posted a twitter thread where he discussed the use of exposure in painting. Exposure is a photography concept, concerning the amount of light that is allowed to enter the lens. This can be controlled by adjusting the shutter speed and lens aperture. 

I never considered this concept in regards to drawing or painting until I read this thread. It is such an eye opener to think about this concept in regard to storyboarding, especially when you work on a scene where the lighting is a big part of the story. (For example: a scene set in a shady bar, or by a campfire, a romantic candle-lit dinner, a character locked in a dungeon...) 

Below is a full transcript of his twitter thread, he has more great twitter tutorials here.  

How often do you think about exposure when starting? How do we go from a lot of information to something we can actually paint? Organizing values and colors is a big part of successful painting and exposure is a method to plan that out.

When painting from life, it is tempting to copy the exact colors/value you see, especially with even lighting. With strong light, the problem becomes obvious: paint, pencil, etc. can't reach the levels of light and dark that we see. The solution is to compare and compress! Paint can’t be as bright as a lightbulb or as dark as the deepest shadow, so how do we paint them? We can omit information so that the *relationships* of values are correct, reconstruct a world with its own internal logic, and then use this to control the composition.

You’re taking a phone picture: you want to show the detail on a lightbulb, so you tap on it and all the shadows go black but detail comes into the bulb. You want to show information in sunlit deep shadows, so the light goes white but reflected light detail emerges.

If a real life scene we want to paint has a range of information from -1000 to 1000, and our paint value scale is only 0 to 10, then each value step will represent a factor of 200! This shows why we need to keep the values subtle and controlled, since each jump represents a lot!

With bright sunlight we have a choice: expose for the light or for the shadow? If exposing for the light, try using one value in the shadow and two in the light. This way we can get a ton of form information in the light and the flat shadow value is still relatively correct!

If exposing for the shadow, try using one value in the light and two in the shadow. This way we can get brilliant color information in the shadow and the relationship with the overexposed light still makes sense!

If it seems like we can copy values with dim light, we should still think about values in a relative way. If we only paint easy things it is hard to learn comparative values, difficult subjects with big value ranges teaches this lesson and it should carry over to other subjects. Light has a unifying effect: grouped values are kept very close. Keep the areas of light and shadow distinct. When we do this, the important stuff like the drawing, shapes, and composition can now be focused on like arranging simple strips of construction paper. 

(Artist credit: Abram Arkhipov)