This photograph shows three spheres with varying surfaces. The one on the left is matte, the one in the middle is glossy, and the one on the right is highly reflective.
On the matte sphere there is no highlight. On the glossy sphere in the middle, the highlight is clearly apparent. The mirror-like sphere on the right also has a highlight, which is really a reflection of the light source. The light source is the sun shining through a window.
The right sphere also reflects the scene around the ball, including the white paper background and the dark room behind the camera. In the right ball, you can even see a reflection of the middle ball, with a highlight in the middle of that reflection.
That same pattern of reflections of the paper, room, and neighboring ball is subtly visible in the middle ball as well.
In the middle ball, there is a second, smaller highlight just to the right of the primary highlight. This secondary highlight is the sunlight is reflected three times.
The light bounces off the middle ball, bounces back off the right ball, and bounces again
off that little highlight on middle ball back to your eye.
So we've arrived at a definition: A highlight is a specular reflection (Latin "speculum"=mirror) of the light source on a shiny surface. The shinier and smoother the surface, the brighter and clearer the highlight.
These three diagrams show what's happening at the surface level. On the matte surface, light arrives from the top left and hits the rough surface. Some light gets absorbed and the rest scatters away in all directions. This is what happens when light hits a matte surface like a sand dune or a sweater.
The glossy surface of the middle ball bounces a a portion of the light at the same relative angle as the incoming light, but some of the light rays hit uneven spots and bounce in random directions. This is like bouncing a golf ball on a country road. It will probably bounce the way you want it to unless the golf ball hits a crack or a pebble.
The mirror-like surface is so smooth that all the light bounces off the surface predictably at the same relative angle, like bouncing a ball off a basketball court.
Since highlights belong to the world of specular reflection, they should be thought of as somewhat separate and distinct from the normal modeling factors (light, halftone, and shadow) of diffuse reflection. Artists in the world of 3D computer graphics can control the form-modeling and the specularity as separate components.
I wrote an article on this subject of "highlights and specularity" for the current issue of International Artist magazine, which should be on the newsstands now. This blog post is just a little piece of it.
The six-page article contains a lot more examples and explanation, and it incudes artwork that has never been reproduced in print before. I'll talk more on the blog about highlights in real-world examples tomorrow.
----International Artist magazine, Issue 90
This subject is also covered in my book Color and Light: A Guide for the Realist Painter (Amazon)
, also available signed from my website store.
When you're in first grade you have to get creative to be able to make 40 valentine's and still have fun.
Here is my valentine to you, dear blog. Playing around with my color palette....
A rare day-off for Lincoln's Birthday, the big kids all gone to friends' houses, and a little sunshine on the front patio means that my littlest can have fun playing out front while mom updates things on the laptop.
|Spring flowers have already arrived.|
Anyway, didn't I say I might just tweak the painting a little? Well, that wasn't exactly true. When it came down to it, I think I tweaked it a lot. Of course, it may not look different but, with a little close observation, one might notice differences. Frankly, I became frustrated with the 2 flowers on the right - they became rather muddled by overworking with to many colors - I even completely painted out the bottom one and started over.
|I think it's done - but I'm still not happy with the leaf - I'll just tweak it a little...|
Light was an interesting challenge as I had a changing light source (a south-facing window) to my left which caused moving shadows and a secondary interior light overhead/right which created shadows of its own. I realized that I was giving conflicting information with cast shadows of the flower petals on both sides of the vase/creamer, but I liked the shapes and decided to keep them. And that's what was truly liberating about this project compared with the first one which was much more dependent on observation. For this one, I gave myself permission to use more artistic license and mostly responded to what was happening on the paper. Besides liking the shapes of some of the shadows, I also liked the orange from the flowers reflected on the porcelain surface - it wasn't nearly as pronounced in real life, but I liked it in the painting.
I still have dreams of one do doing a "quick" little still life that captures its essence with a minimum of strokes... (sigh)
Cristian Romero has created a free digital tool for analyzing color schemes. All you have to do is drag a "jpg," "png," or "bmp" into a box, and it will output a gamut map. The gamut map shows which colors are inside the color scheme and which are outside.
Here is a painting by Anders Zorn, showing the narrow range of colors used in the picture. The scheme is centered in yellows and oranges. The "extra-gamut" colors (colors that don't appear in the scheme) are magenta, blue, cyan, and green.
This image has a wider gamut, extending across neutral gray at the center of the circle. It has full intensity yellows and reds as well as some cyan, green, and violet. The gamut doesn't reach all the way to the outer edges of the circle because some hues are only partially saturated.
Here's a fine example of a complementary gamut, a narrow slice of the color wheel from orange to cyan-blue.
The gamut mapping idea is useful both for analyzing color schemes, as we see here, but also for generating the color schemes that you want for your picture.
Further reading and exploration
Christian Romero's KGamut (samples) and free download (Windows only)
There are other digital tools at Live Painting Lessons
There's more about gamut mapping in my book Available on Amazon and signed from my web store.
Previously on GurneyJourney:Gamut Masking, Part 1Gamut Masking, Part 2
(Video link) Using colored flashlights, science presenter Steve Mould explains why the color magenta doesn't appear in the rainbow.
In this optical illusion, the magenta dots switch on and off in series, producing a green afterimage on the retina. The effect is especially strong if you look at the cross in the center. Via Biotele, thanks, Damian J.
Previously on GurneyJourney
Mystery of Magenta
Here's an optical illusion GIF that I created to demonstrate color afterimages. Bring your face close, turn up your screen brightness, and stare at the center of the grid.
(Direct link if the GIF doesn't work
) Every three seconds it switches from bright colors to neutral gray. The afterimage effect tinges the gray squares with the complementary (or opposite) color. The effect doesn't last long because the stimulus is short and the color receptors don't have much time to get depleted.
) The same principle applies to this video, where a color afterimage infuses a black and white photo with the appearance of natural color.
To get the best effect, watch the video at full screen size and stare for the duration of video at the dot in the center. When it switches over to the photo, keep looking at the center. Your retinas have been primed with a seemingly random (but really a complementary) color pattern for a longer period of time. The colors are more stable this time because the depletion is more dramatic.
Most animals have lighter coloration on the belly than on the back. This form of camouflage, called countershading, disguises prey animals by offsetting the effects of shadowing on the bottom surfaces.
When standing in bright sunlight, this Cuvier's gazelle is likely to present an unexpected silhouette to a potential predator.
Countershading is commonly seen in marine animals such as fish as well, darker on the dorsal surfaces and lighter on the ventral surfaces.
Since both predators and prey need to remain hidden, both are frequently countershaded. Both penguins and killer whales evolved from very different terrestrial ancestors, and both developed a similar black and white pattern of coloration.
BIG Pie Party this weekend! It's a fundraiser for the Marsha Rivkin Center for Ovarian Cancer Research. Pie! Pie! Pie! See you there!
On this lovely afternoon, I was able to spend time painting. I realized that the little still life I just painted was OK, but...something about it isn't sitting well with me. I'm happy to be more comfortable working with acrylic paint, but it's still falling flat. That contrast that I like to emphasize just wasn't there once the colors dried. Also, I wanted to try something a little looser now that I'd solved the question of colors and mixing. So, I decided to try it again from a slightly different angle.
|First paint (left) and today's painting (right)|
I definitely like the 2nd one better - it has a greater level of contrast and it is slightly looser (although I think total reckless abandon just isn't how I was created to paint). There's still a little tweaking that I'll do, but it shouldn't change too drastically from this. One thing that I thought about while painting was how much easier color mixing has become. In the early days of painting, color mixing was a little confusing - sort of hit or miss. But now, I have a better sense of whether I should add a blue, a brown, or a black for a shadow; whether I should add a white, a yellow, an ochre, or some other color for a highlight. I'm actually quite happy with my painting now - I want to have one foot in the natural world and one foot in the expressive without swinging too far one way or another...at least for now.
|This doesn't exactly accurately represent the saturation of some of the colors, but it's close...|
I've been watching some art programs on the Ovation channel lately and I had to pause one episode of Art in Progress to write down a quote. The show focused on the artist Donald Sultan
- I was not particularly familiar with his work and I liked it to some degree, although it was a bit to conceptual for my tastes (a topic for another time). But, he said something that really struck a chord in me as I so often "overthink" things."One of the mainstays of making art is that you don't think of new ideas - you discover them. So, that's why you have to work all the time. If you go out and just lie around and start thinking and waiting, you know nothing is ever gonna happen. And, the longer you wait, the more you realize that when you come back to it, you're right back where you were. You're not any further along even though you thought and thought and thought - you didn't really go anywhere." Donald Sultan
I appreciated this thought since I often like to spend time - too much time - thinking about what I want to do. And, sometimes it's paralyzing.