Tag Archives: light

The liquid crystal display explained!

Three inventions moved clocks and watches away from being mechanical/analogue so they could become digital: The quartz crystal, the circuit board and the liquid crystal display.

Okay, I sort of explained how a battery works. I kind of explained how a quartz crystal works. The circuit board was easy—even a shmo like me can explain printed metallic ink on a plastic card. But—liquid crystal display? I started this post about 17 times and kept getting lost in the weeds with carrot juice and double melting points and twisted nematics and polarization…

Let’s start here: analogue clocks and watches were inaccurate because they have physical, mechanical moving parts. So we replaced the wound-up mainspring with a battery. We replaced the balance wheel with a vibrating quartz crystal. Now we need to replace the moving mechanical gears, hour-hand and minute-hand with a digital (just the numbers) display of the correct time. How do we do that?

A digital wristwatch made by the Japanese company Casio.

Instead of mechanical gears and hands, we’re going to use electricity and light.

We want a watch-face that will light up and show us what time it is. We want most of the face to light up except the numbers, which should be black so we can read ‘em easily. We’ll block the light in the shape of each number so it shows up black. The numbers will change every minute, so we need a way to change the blocked areas every minute.

In order to block the light, we need a filter. The filter lets us control which rays of light pass through and which rays get blocked. A filter could be a wall of liquid filled with crystals that all face the same direction. The lined-up crystals let the light pass through. We’ll sandwich this wall between 2 plates of glass. The crystals still let light pass through—until we zap them with a little electricity. The electricity upsets the crystals so they don’t line up anymore and light can’t pass through.

We’re only going to zap in certain areas. We want those certain areas to be shaped like numbers. For instance, when we zap the glass in the shape of a ‘3,’ those crystals in the 3-shape get upset and don’t line up with the rest of the crystals in the wall. Light can’t pass through the 3-shape, so we see a black ‘3’ on a lighted watch-face.

Just like on a circuit board, we’ll print the numbers onto the glass in ink. This ink is transparent—and it conducts electricity. Each number is designed as a 7-segment figure, so we can zap only the segments that form a ‘3,’ or whichever number we want. Each segment is wired to the battery.

This is the principle behind LCDs. It’s a simplification. I left out a lot of stuff. But you get the idea, right?


https://electronics.howstuffworks.com/lcd.htm
https://electronics.howstuffworks.com/gadgets/clocks-watches/difference-between-quartz-and-liquid-crystal2.htm
http://www.madehow.com/Volume-1/Liquid-Crystal-Display-LCD.html

Many thanks to a couple of the Western Civ Irregulars, Diana (Ms Physics) and engineering-wiz Don M—both pals of mine since childhood. They pointed me in the right direction when I couldn’t find a way to explain this one.

Back to the beginning of The Western Civ User’s Guide to Time & Space

What do I paint second?

Michael asks:

Thanks so much for posting your technique, I am currently working on my first painting and have been doing exactly what you’ve done here. i think i did do something wrong though, a friend of mine said to do a light wash over the entire piece ,but I think it just confused me. Anyhow , why do you not put more detail in the underpainting, are you modeling further with your glazes?

I’m not sure what the light wash is for, either.  I’m assuming you’re using acrylic paints, which dry to a hard finish and so allow you to paint a wash on top of them.  I use gouache, and a wash would scrub off whatever was painted underneath.  So, I start my paintings with washes and build up to opaque brushstrokes. A wash is paint made transparent by adding water.  A glaze is paint made transparent by adding a medium—for acrylic, glazing medium; for oil paint, linseed oil and varnish—or glazing medium.

I do an underpainting to block in and organize big areas of light and dark.  I long ago found out it’s too complicated for me to figure out light and dark and color all at the same time.  There’s no point in me putting lots of detail in the underpainting, because I’m only going to paint the same details on top with opaque paint.  In fact, to discourage myself from getting into details while underpainting, I use an oversized brush.

Here’s a step-by-step example of how I build up from an underpainting.  This is a continuation of a previous post, What do I paint first?

Hide and shriek!

Here’s the opening spread from Where’s My Mummy? This scene shows Mama Mummy getting Baby Mummy ready for bed—but Baby wants to play one more round of hide & shriek.

Since they’re mummies, I designed an interior to look like the inside of a pyramid, with lots of Egyptian details.  The legendary art director at Candlewick, Caroline Lawrence, felt the setting didn’t convey enough ghoulishness, so she asked me to redraw the scene with a gothic interior.

mummy0607

Revised sketch with gothic details below.  Architecture geeks will note the new shape of the columns, rough-hewn stone walls and groined vault arched ceiling.

mummy.revise.0607

I changed the oil-burning lamp to a candelabrum, but doused the candles in the color version because they were causing me lighting/shadow problems.  I kept the sarcophagus bed from the first sketch.

mummy_01

The light is coming from a single source.  More dramatic and easier to paint.  Also, the viewer’s eye naturally looks to the light source, which is where I put Baby Mummy.

 

Fireflies

I want to warn you ahead of time that I don’t have the finished illustration that would normally follow the series of sketches below.  I must have gotten rid of it, or else it’s boxed away somewhere in my attic (I moved last November and am still unpacking).

A while back I got an assignment to illustrate a cover for a summer issue of StoryWorks magazine.  The art director asked for fireflies reading books. Sounds like a fun idea—I went to work drawing variations of it.

The first one works, but it’s kind of the obvious solution:

firefly.book

I like this next one in spite of its being a little weird.  To make it work I’d need to really play up the lighting effects:

firefly.bed

Fireflies reading books in a bookstore after hours:

firefly.bookstore

Fireflies combining their individual lights to read a book:

firefly.jar

Firefly using a flashlight, with a farm in the background:

firefly.farm

And here are fireflies using each other’s butts to read by:

firefly.circle

Those were the ideas I came up with.  The AD liked the last two, couldn’t decide which one to use—and asked me to combine them in one sketch:

newfirefly

I wasn’t happy with it.  Too many elements, too difficult to read the idea.  I would have loved to paint any of the other sketches, but it wasn’t meant to be.  Nobody’s fault; the art director and I just had different tastes.  That’s the way it goes sometimes.  You do your work, get your paycheck, and move on.

From the archives—Señor Don Gato

Here’s a book I did a while ago—Señor Don Gato. Due to a copyright dispute, it’s no longer in print.  This project was a turning-point in my style.  I closely studied the work of Diego Velasquez: his palette, composition and lighting.  By limiting my range of color and paying attention to how a subject is lighted, my illustrations became less cartoony and more painterly.

Here’s a sketch.  Don Gato receives a letter from his lady-love and reads it on a high red roof:

9.sketch

And the final painting:

9.final

This painting below was never part of the book. I did it to get a feel for Velasquez’ painting technique.

Gato.study

Here is the portrait by Velasquez that inspired my painting of el Don.

large_275px-DiegoVelazquez_JuandePareja

If you’d like a copy of Señor Don Gato, shoot me an e-mail at Jmanders@aol.com.  I have a small stash of mint-condition copies and I’ll be happy to autograph them for you.  I’m charging $40 per copy.  Half of that will go to the Venango County Humane Society.  I promise to do some kind of big cardboard check photo op so you know I didn’t keep all the cash for myself.  The offer’s good til I run out of books.

Underpainting

When I paint, my favorite medium is gouache (rhymes with squash).  It’s opaque watercolor and versatile: I can water the colors down to transparency or paint them on thick and opaque.  If I need to make a change after the paint’s dry, I can soak off most of the paint with a damp paper towel and start over.

Since my style is so cartoony—which was not a selling point with children’s art directors when I started out—I learned to paint in a classic sort of way.  My goal is to make objects in my pictures look three-dimensional by modeling them, by rendering the light and shadow.

Figuring out light and shadow while worrying about color is not easy!  I found it’s simplest to separate the two activities.  I paint light and shadow first, then add color on top later.

The first step is called underpainting.  I like to use a warm brown, Burnt Sienna, for that step.

Here’s a page from Where’s My Mummy? another collaboration with my pal Carolyn Crimi. This story is about Baby Mummy’s one last game of hide-and-go-shriek before bedtime.  All the monsters in the graveyard are getting ready for bed.

51GQNH0m+LL._SL500_AA240_

I should mention that as usual, I was behind schedule with this project and got lots of painting help from the talented Rhonda Libbey, who blocked in big areas of color.

Okay, first the sketch:

mummy.revise.08

You can already see many of the shadows in the sketch.  The scene’s a graveyard, so shadows are important for mood.  Here are the shadows painted in Burnt Sienna:

mum.ip.08

You should be able to tell from which direction the light’s coming.  I try to avoid detail in the underpainting and concentrate on the masses of light and dark.  It’s really an abstract design.  I didn’t paint the vines growing on the tombstones, for instance.  Now here’s the color painted on top of the warm brown underpainting:

mum.ip.08a

I was trying to evoke those old black and white monster movies, so I used a very restrained palette, or range of colors.  There are few bright colors in this book.

One of the nice things about the warm Burnt Sienna underpainting is that it peeks through the cold neutral overpainting here and there.  I think that the underpainting also helps to unify the illustration by giving all the colors something in common.

You’ll notice that I haven’t yet painted the Baby Mummy.  First I paint my backgounds, then  I paint the characters.  That helps me keep all those elements consistent throughout the 32-page book.

Here’s another image—in progress—from the same book.  I haven’t painted the characters yet, just the background.

mum.ip.20

And here’s the finished painting.  Dracula gets a bright red bathrobe.

mummy_03

This one is near, that one is far

When I talk about perspective, I’m talking about how an artist creates the illusion of distance in a flat drawing or painting.  Two ways to do that are 1) make the nearer object big and the farther object small, and 2) make the nearer object dark and the farther object light.

Here are some sketches from Henry & the Crazed Chicken Pirates.

We kids’ book illustrators are responsible for telling the author’s story in pictures.  So, when I work on a project, my first drawings are thumbnail sketches.  These are pretty small: maybe only an inch and a half tall.  Because they’re so tiny, I can draw them quickly and best of all, fit all of the scenes onto a single 18″ x 24″ piece of layout paper.  That way I can see the whole story at once.

1213.tn.chickens

Here’s the thumbnail sketch for pages 14/15.  It’s pretty rough, but everything is there.  Another huge advantage to working so small is that the image’s composition becomes clear and simple.  Notice the contrasts:  Henry, in the foreground, is big and dark; the balloon, in the background, is small and light.

Atmospheric perspective is a technique Leonardo, Raphael and the rest of the boys came up with during the Renaissance.  Things that are close to us are sharp and contrasty, things that are far away are muted and softer.  If you are looking at a mountain off in the distance, its colors are softer because you’re seeing them through air that’s full of dust, water particles, cigar smoke, car exhaust, bird poop, &c.

H&CC1415

Spread 14/15

The comprehensive sketch is more refined but I’ve kept to the same composition.

By the way, those parrots are inspired by my parrot, Sherman.

IMGP1186

Wacka-wacka!

Sometimes the thumbnail isn’t quite doing the job, and the comprehensive sketch will change—and improve—what I’ve tried to do in the thumbnail version.  Here’s pages 20/21.

1819.tn.chickens

In the thumbnail version, these pages look a little confusing together.  On the left, Henry’s gaze and pointing finger lead the reader away from the spread.  It’s always a good idea to direct the reader’s attention into the spread, not out of it.  Also, the right side is okay, but not inspired.

H&CC2000

Left-hand page.  By taking Henry out of the picture and just showing the book, we’ve improved the image: the bunny’s gone, so he can’t point outside of the picture.

H&CC2100

Right-hand page.  Yeah, much better.  A treetop lookout for Henry allows me to create a cinematic image, with dramatic perspective.  Henry is way up high and close to us and the Salty Carrot is below and far away.  The great height adds dramatic tension to the scene (will he fall off the ladder?), making it more important.

henry.2100

All the dark, rich colors are near to us: the tree and Henry.  No dark colors were used at all to paint the ship and palm trees below.