Tuesday, March 29, 2016

Lens Flare for Painters

Whether you call it lens flare (what happens in a camera when you look at the sun) or color corona (a similar phenomenon that happens in your eye), it's a powerful effect that's popular in photography and video these days, but it's also something that has fascinated painters for a long time.

Peder Mønsted, A Winter's Day
The painting above was done in 1918, before color photography would have been in common use, so it's almost surely based on the effect that you can observe with your eyes. However, I don't recommend looking directly at the sun, which can damage your eyes.

The effect comes from light scattered by water vapor and dust in the air between you and the sun. The light is further scattered by your eyelashes when you squint, and then by the aqueous humor and vitreous fluid of the eye. The effect is best observed when you glimpse a setting sun through trees or when you see a streetlight at night.

Try squinting hard at a streetlight and tilting your head to see how the rays tilt with you. Also, try walking through the forest where the sun is mostly blocked by branches and glance up toward the sun as you walk to see how the corona comes and goes.

Giuseppe Pellizza (Italian, 1868-1907) Volpedo, The Sun, 1904
Both Mønsted and Pellizza show the corona with lines radiating from the sun. They also observe a shift from yellow into red. Pellizza breaks the effect into particles of varied color. Note how simply and softly he paints the foreground areas.

Lens flare is easy for digital artists to add, and a little harder for physical painters, depending on the technique. As a photographic effect, it has origins in camera optics. Its artistic use—and overuse—in film, television, and photography is well explained in this Vox video (link to YouTube). Thanks, Dan.
Related GurneyJourney posts:
Color Corona
How to Get a Feeling of Misty Light
Practical Lights
Light Spill

More of this kind of stuff in my book Color and Light: A Guide for the Realist Painter


Eugene Arenhaus said...

AFAIK, the "rays" of a point light source like a star are the result of refraction in the lens, not the vitreous fluid or cornea. The lens is composed from sectors, and normally the difference in refraction is too minute to notice, but a point light source brings the boundaries between the sectors out.

James Gurney said...

Eugene, what a cool piece of information. Thanks for that.

MoStarkey said...

Lens Flares have become cliché in the demo reels and portfolios of computer game artists. Most art programs can handle them with a key click. The PC can do all sorts of technical light effect. I actually had a student tell me the reason he used it so much was because it was an effect that a painter couldn't do on their own. I insisted, with good observation skills and some experimenting, he could get these effects with out a computer. I'll have to show him these examples. Thank you so much, James.


Unknown said...

That flare is such a great effect but so easy to overuse. I always think of long tree shadows backlit with a bit of sun glaring. It's how we see it. But night scenes in cities look great with the lens flare effect adding to the action of the scene and that's not how we really see it at all.
Just so easy to overdo it.

Eugene Arenhaus said...

Happy to help, James. :)