Wednesday, May 6, 2009

Edges in Moonlight

When you go out on a moonlit night, away from streetlights, can you see the cracks in the sidewalk? How about the blades of grass, the clapboards on a house or the small twigs and branches?

Unless you’re a cat or an owl, these smaller details melt into the larger shapes. Everything has blurry edges. The reason visual acuity drops off at night is because the central point of vision where we see small detail is filled with photoreceptors that only work best in bright light.

James Perry Wilson, the artist famous for his diorama backdrops, conveyed this subjective experience in this architectural rendering. He softened the edges and suppressed the detail everywhere except in the brightly-lit windows where the light levels are higher.

Assuming that he wanted to simulate this perceived effect, this rendering by Edward McDonald is not quite as effective because he kept all of his edges too sharp.

If you use night photography as reference, remember that the camera doesn’t see as the eye does, and you have to make this adjustment if you want to suggest human vision.
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Related GJ posts:
James Perry Wilson, Part 1 and Part 2
Why moonlight is blue.
Day for night shooting.

Images from "Color in Sketching and Rendering" by Arthur Guptill. It's a book on watercolor rendering, mainly of architectural subjects, with lots of color plates, one of Guptill's best books.

14 comments:

K. W. Broad said...

Oh wow, thanks for the advice! I happen to be working on a painting with a lot of shadow and low-light, and I think fixing some of my sharp edges will definitely help!

Melissæ said...

Thanks for the insight!

Steve said...

Frederic Remington was fascinated by the challenge of painting night-lit scenes. Several of those paintings were collected into one excellent book...Frederic Remington: The Color of Night.

Thanks for another great post!

Moai said...

I've noticed how soft edges and details can get in low light. That first painting does a great job of capturing this effect.

Jon Hrubesch said...

I don't know how to paint a blurry scene with real paint. To create this effect with photoshop I suppose you could just use a Gaussian blur on a layer copy then erase to the original layer near the brighter lit areas. Maybe you could explain your technique for creating a blur in a future post.

foxstudio said...

I haven't tried a night scene, but when I do, I'll definitely keep this in mind. Great advice!

Oscar Baechler said...

There's a blurb in Andrew Loomis' "Creative Illustration" by Howard Pyle about how to deal with light and dark details, which says that in your lit areas there's details from minute shadows getting cast by hair, goose bumps, scales, etc., but in your core and cast shadows there's little detail, because these minute textural bumps have both their mini-shadows and mini-highlights all engulfed in dark.

Would you say this is akin to that principle? As in, since the whole scene has a general darkness (other than in manmade sources of light) there's nothing for highlights to come up from?

Erik Bongers said...

Oscar:
The lack of detail in shadows in a 'normal' lit scene is due to the fact that typically shadows are lit by indirect light bouncing back from about everywhere (in the room), thus resulting in difuse light and soft highlights/shadows, while the directly lit areas receive most of their light from a single source, resulting in a highter light/shadow difference.

It's only when things get very dark (like with moonlight) that our eyes add some more blur the whole scene. But that blur has nothing to do with the scene itself.

Mark Heng said...

Looking at the first picture, the word "sfumato" comes to mind...If you look at it long enough, there's a slight sensation of smokiness between yourself and the subject. Very Cool!

Daroo said...

This is probably why the old westerns that were shot "Day for Night" weren't that effective. Though the filters darkened or, if in color, turned everything blue, (see previous posts)they didn't do anything to reduce the contrast. All the edges were in sharp focus.

As your excellent post "Why moonlight is blue" shows, they can probably now run the raw daylight footage through a digital filter that would mimic night color shifts and differing levels of contrast or diffusion in the shadows and the light. Anybody know if this is being done? Examples?

I remember seeing some old B-western where the characters were squinting and subconsciously shielding their eyes from the light -- during the middle of the night!

Brine Blank said...

Funny how what is 'right' is so often counter to what we 'want' in portraying certain subject matter...I know sometimes there is a different intent by the artist but comparing the two paintings really drives your point home...great post and continue to enjoy the educational insights...

James Gurney said...

Oscar, I think Erik answered your question better than I could. Pyle is right that texture is usually more obvious in the light side of a form that's lit from a sun or moonlit source. It's the dimness of the moonlight and the failure of our eyes to work well in that low light that accounts for the lack of detailed texture that we see at night.

asterius said...

The several posts here have been a great help to me and some of the members of an art event we created called the "artists safari". Nearly every full moon here in Perth (Australia) we've been going out to draw and paint. I would recommend it to others on this blog because it forces you to learn the basic drawing of masses of tone. It is surprisingly easy and de-stressing as well.

jeff

James Gurney said...

Great comments, everyone. Jeff, what medium/size do you use when you work in moonlight? Do you work in black and white, or some color?