Monday, February 9, 2015

Patchwork Visual Spectrum Scarf



Naturally, I've got Color Theory on the brain, and I've been thinking a lot about light lately - and one night when I couldn't sleep, the idea for making this visual spectrum patchwork scarf popped in my head. And then it was all I could think about until I could make it!

Light is energy, and although we mostly perceive light as "white", it contains all the colors of the spectrum. You're probably familiar with this little nugget of knowledge from somewhere deep in your grade school past - Newton's light refraction experiment with a prism.


It goes like this - light travels in waves, all of the wavelengths together create white light. When travelling through a glass prism, the light wavelengths are split up or refracted, allowing us to see the different wavelengths as they appear in different colors. Quick - check out this awesome video explanation of the experiment.

As shown in the video, each of the colors of light spreading out has a measurable wavelength. Think about waves in the ocean - you can see the top of the wave, the crest, and in between each wave is a low point - like a valley. The waves of light are similar, and are measured from the top crest of one wave to the crest of the next.


These waves of light are very, very tiny and are measured in nanometers. Check out this video to get an idea of just how small a nanometer is! Red light waves are the longest, and diminish in length through the spectrum to violet, which has the shortest wavelength. Above is our visual spectrum of light as measured by their waves in nanometers.

Although the bands of light as seen refracted through a prism look about the same regardless of the light waves (the red band doesn't appear any wider than the violet band, although the red wavelengths measure about 700nm while violet waves are about 400nm), I decided to make my scarf a representation of the different wavelengths of the spectral colors.


So my idea was this - if red waves are the longest at about 700nm, with violet the shortest at about 400nm, and green is in between at about 5nm, then my bands of colored fabric would correspond in inches. At one end the red band is about 7.00 inches (to represent 700nm), in between the green band is about 5.00 inches (to represent 500nm), and at the other end the violet band is about 4.00 inches (to represent 400nm). All the other colors fall out in between, from longest bands representing the longest wavelengths down to the shortest.

This isn't a full tutorial, but I will share a bit of the process with you.


First, I created some improvisationally pieced fabric rectangles. Since this is a scarf made with just the fabric (no batting or extra layers), I used a very small stitch length while piecing - like 1.75mm. I also pressed all seams open, then top-stitched the seam allowances down from the top so that they would not get all crazy inside the finished scarf, or start to unravel. You can see one of the pressed open and topstitched seams in this photo of stitching some of the patchwork together.


As I cut each panel to size, I stitched them together using a 1/4 inch seam, pressed seams open and topstitched the seam allowances. Here's what it starts looking like.



Patchwork pieces all finished and stitched together. At this point the patchwork measures 13" wide and over 70 inches long.



Next, I pinned the long edges right sides together and stitched with a 1/2 inch seam allowance.


And pressed the long seam open all the way.


I took a few tacking stitches through the back scarf seam, using the free arm of the sewing machine to reach inside. I did this to help keep the seams flattened inside the scarf, and stitched along the seams between each of the color bands.


Then I pinned and stitched closed the ends of the scarf with a 1/2 inch seam allowance, leaving an opening 3 inches long at one end for turning the scarf right side out.


Turned the scarf inside out, pressed, and hand-stitched the opening closed.

 
On final pressing, I used a clapper to get the scarf nice and flat.
 
 
 After a trip through the washer and dryer, it's actually very cozy!
 
 
 
Loving it, and the best part to me is the reminder of how the colors we see are different vibrating waves of energy!



Friday, January 16, 2015

Three Is The Magic Number

Remember in the last post we looked at rodsand cones in the human eye? Cones are the photoreceptors in your eyes responsible for detecting colors, there are THREE different types of color cones, and this is how the process works.

Here’s a quick analogy for our eye’s color receptors. It’s a little like viewing pixels on an old LCD screen, did you ever look super up-close at an LCD computer screen? LCD screen displays are based on pixels that produce light in three colors; red, green and blue. Coincidentally, the three different color receptors in our eyes detect the same three colors of light; red, green, and blue.

 
Up close, you can see each individual pixel.
      
 

Look a little farther back, and you can see how each pixel lights up to create the illusion of all the colors (or no color, which displays as black). Get far enough away from the screen, and you don’t even notice the pixels.

When red, green, and blue light mix or blend together, it actually creates new, different colors. However, no matter what other colors of light you mix together, you cannot create red, green, or blue light. In the color system of light, red, green, and blue are the first or primary colors; all other colors can be mixed from them. Like this picture.



Where the primary colors of light come together in the center (red, green, and blue), it creates white light. When just two colors overlap, a new color is created. Red and green light make yellow. Green and blue light make cyan. Blue and red light make magenta. These are called the secondary colors, because they are each a mix of the two primaries. To expand further, you can mix secondary colors with primaries again, and in different amounts, to create even more colors.



In the color wheel above, red and yellow light mix to make orange. Blue and magenta mix to make violet – and so on.

The color system of light has three primary colors; red, green, and blue. When these primary colors mix together in different amounts, all the other colors (yeah, ALL the other colors) are created. A perfect mix of the three primaries makes white light; a lack of all three primaries results in black.

The color system of light is called Additive Color (because three primary colors of light are added together to create all others), and can be abbreviated as RGB (for red, green, and blue – the primary colors in this system). (If you are used to seeing the artists color wheel with red, yellow, and blue as the primaries, this might be a bit confusing. Don't get too hung up about it, just know that the artists color wheel is a different color system called Subtractive Color, sometimes abbreviated as RYB.)

To sum up, take a quick look at this awesome video lesson on How We See Color.

Look at this apple. Right now, the red photoreceptors are being stimulated in your eyes and are firing off signals to your brain. Your brain is telling you this color is RED.

 

Now, what about this apple?

 
Right now both red and green photoreceptors are firing off in your eyes, and as the red and green receptors combine to make yellow, your brain is telling you YELLOW.

Get it? Okay! Although our eyes have developed to work this way, there are some limitations that can lead to some pretty interesting optical illusions. Some of these optical illusions (and the science behind them) form the basis for part of the study of Color Theory; the interaction between colors. So have fun with these eye games!


Gradient Illusion



The gray bar in the center of the picture appears to be lighter at one end and darker at the other. But, place your fingers over the middle of the bar and you will find that the bar is a solid color - only the background is different in shade.  

Simultaneous Contrast

 


The center squares appear to be different shades of gray, but are actually one in the same shade. Different shades in the background squares create the optical illusion that the center squares are all different.
 
 



The same effect with colors.

 
A similar effect with a solid color on gradients can be found here.
 
 
After Images





Stare at the small dot in the center of the flag for 20 Mississippi's, then look at a blank wall or white piece of paper. Your color receptors start to fatigue after staring at the image, and start to slow down the signals being sent to your brain. After finally looking away, you see the exact opposite (or complimentary) color!
 
Pattern Recognition

 



There's no square in the picture above, but your brain sure sees one! That's pattern recognition in the brain for you, always trying to connect the dots.

Try these links also for even more optical illusions! A big list of optical illusions at Distractify, and 10 more at Psychology.com.

Next post we will look at a little history behind color systems and the color wheel, because parts of color theory are based in using these tools. Until then, do you know RoyG. Biv?
 

Saturday, January 10, 2015

What Does Your Eye See?

We’ve looked at some of the basic principles of visible light, but how does your eye “see” that light?

Your eye is a sphere, has one small opening at the front to allow light to enter, and is coated at the back with cells that respond to light.
http://astro-canada.ca/_en/a2301.php
 
Don’t worry about all the terms in the illustration above, just take note that the light enters through the lens and is directed to the retina. No pop-quizzes or final exams, okay?

Let's check out an age-old but simple illustration of how your eye works, the Camera Obscura. Ancient philosophers were aware of what happens on a bright day in a darkened room when light is allowed to enter through a very small pinhole in one side of the room. A detailed image of what’s outside the room will appear on the opposite wall, flipped upside down.


This phenomenon has been termed “Camera Obscura,” a Latin phrase translated literally as “dark chamber.” Arab philosopher Abu Ali al-Hasan, a.k.a. Alhazen (965 – 1040 AD) recorded his experiments with light, including playing around with the camera obscura. Alhazan not only wrote extensively about optics, working with prisms and refracted light 700 years before Newton, but was the first to understand how the human eye really worked.

Try making your own camera obscura with this tutorial!

 

Or go all out and transform an entire room into one giant modern camera obscura!



Your eye works in a similar way when viewing an image, and yes, the images entering your eye are totally upside down!

As you’ll discover if you play with your own camera obscura viewer, it works great with bright light, but won't show an image in low light. You might be thinking hey, just make the hole bigger to let in more light, right? But if you make the hole too large, the image will no longer appear in sharp focus, and you’ll just see a blob of light.


Try this one – grab a magnifying glass and a white piece of paper. Stand near a strong light source, light a light or a brightly lit window. Hold the paper in one hand, and place the magnifying glass between the light source and the paper. Move the magnifying glass back and forth until an image appears - and notice how the image goes out of focus just by moving the lens slightly. Check out that just as in the camera obscura, the image appears upside down.

 
 

Using a lens is a way to focus an image while using a larger hole to allow in more light. Your eye utilizes a lens along with an opening that can change from super small to let in just a little light to a bigger opening in order to let in more light - it's how your eyes adapt to different light situations to still see a clear image. Just as you can move the magnifying glass back and forth to focus the image on the paper, your eye has the ability to focus, too. Right now, look at something far away from you across the room - then back at your computer again - and notice your eye changing focus!

 
Awesome, right? Now, what happens once that crisp and clear image is focused through the opening and lens on the retina at the back of your eye?
 
Your retina is covered with cells that respond to light called photoreceptors. There are two types of photoreceptors in your eyes, rods and cones. Click and watch this quick video to learn the basic differences between rods and cones. The rods live mostly around the edge of the retina, and the cones are concentrated right in the center.

 
Next, check out this video for a cool microscopic view of the eye, and an explanation of color perception on a molecular level.
 
The important difference between the two types of photoreceptors is this: rods are responsible for light/dark vision working in low-light situations, while cones are responsible for color recognition working best with ample light.
 
Cones also come in three color-receiving flavors; red, green, and blue. How you perceive different colors, and even the color white, happen when several of the color cones fire at the same time. It may be like looking at a pixilated color photo or a Georges Seurat painting. We don’t experience the image that way because our brain is processing the signals from the photoreceptors into all kinds of color blends, shades, and tints (and even more about the brain’s response to color in the next post).
 
Are you still with me? Light enters your eyes through a small hole, a lens focuses the image on the retina, and photoreceptors called rods and cones receive both light and color information from the image. And that is how your eye “sees.”
What your eye sees isn’t at all what you perceive, because your brain is constantly processing and adjusting that image for you.
 
 

On the left, what the raw-image from your eye might look like before being "read" by your bran. On the right, the image you perceive.
 
Because eyes are physiological structures, they’re not all the same. Which means that how you see color may not be the same way that I see color. Word! Check this out:
 
  • We are all born color blind as our eyes are still developing after birth. By about 6 months of age, our sense of color will become fully developed.
  • Color blind people are missing one or more of the three types of color rods in the eye, and men are more likely to be color blind than women.
  • An average human eye can detect over 10 million different colors and over 500 shades of gray.
  • A small percent of women have extra retinal cones allowing the perception of over 100 million different colors.
  • Physiological limitations in your eye also cause a few interesting optical illusions such as afterimages and Mach Bands, click to check it out.
 
The fact that eyes are the first step in our personal interaction with color, and that eyes are not always perfect, means that there can be differences in the way some of us see color. Just another reason why, if you love and work with color in your craft or art, it’s important to learn the language of color theory. Color theory can give you finite tools to discuss, perceive, communicate, and use color more effectively.
 
Stay tuned, next up we’ll look at your brain on color!

Make Your Own Camera Obscura



A fun experiment to learn about the properties of light and how your eye sees!


What you need:
  • One empty smallish cardboard box
  • Tracing paper
  • Scissors
  • Large sewing needle
  • Tape

Look for a smallish box about 3" wide between what will be come the front and the back of your camera obscura. These snack-pack boxes work great!

STEP 1


Cut a viewing window open on one side of the box about 4"- 5", making sure to leave at least 1" of box around the opening.

STEP 2



Cut a piece of tracing paper to fit over the window, overlapping on all sides. Tape in place.

STEP 3


Tape both ends of the box closed tightly so that no extra light can enter the box.

STEP 4


Poke a pinhole in the center front of the box using a sewing needle. Be careful, and start small! If you make the hole too large, your camera obscura won't work.

To see if your camera obscura is working, hold it up to a really bright light source, like a light bulb. If you don't see an image, make your pinhole a little bit bigger until you do.


To use your camera obscura, point it at a very bright light source, like a sunny window...


Or drape a heavy, dark towel over your head and drape around the camera obscura to see much more detailed images.

Read more about camera obscura here, or follow this tutorial to turn a room into one GIANT camera obscura!

Wednesday, January 7, 2015

What Color Do You See?

If you're a color lover like me, then I hope you enjoy the first of several posts on the subject of Color Theory! 
 

When you look at an apple (unless you are color blind) you can easily identify the color in a split second as RED. How you “see” that red apple is really a fascinating process; one that involves the physical properties of light, the hardware or physiological structure of your eyes, and psychological process in your brain. 

Illustration from DotColor.com

Let’s start with the first part of the puzzle, the physical properties of LIGHT.

It’s hard to get a handle on exactly what light is. We take light for granted; we live with it each and every day, and we can’t see without it. I think Astrophysicist Neil deGrasse Tyson summed it up best by saying, “Color is the way our eyes perceive how energetic light waves are.”

Because that’s all light is – waves of energy. In fact, the light we see is part of a larger system of waves called the Electromagnetic Spectrum that includes a bunch of other kinds of energy waves, from radio to gamma rays.
 




Waves of energy pictured above are measured from one “crest” of a wave to the next – and in the chart you’ll see that the largest waves (as big as a football field from the crest of one wave to the next) are broadcast radio waves. The shortest, gamma rays (and yes, every time I read “gamma rays” I hear this) are even smaller than one single atom from the crest of one wave to the next.

The light we can see, which in the electromagnetic spectrum is referred to as visible light, has amazing properties. Visible light travels as energy waves in an incredibly straight line and mind-blowingly fast. I say light travels at mind-blowing speeds because as human beings light speed is like the fastest thing we can comprehend – it actually defines the speed limit for energy. For us, the speed of light itself is absolute – it is a constant, and does not follow any other laws of motion or classic relativity.

Okay, but yes, we’re talking about light today! The important thing to focus on is the visible light in the electromagnetic spectrum above, and how it is displayed as a rainbow of colors. These specral colors, each a different wavelength living right next to each other, all travel together to make white light.

Newton was the first to really discover and understand this simple principle; that the light we see as white is really a compound of a full spectrum of colors. Newton is also credited with the arrangement of the colors in a wheel, which has evolved into our current day artist’s color wheel.
 


Illustration from Encyclopedia Britannica

In Newton’s experiment, white light travelling in a straight line is passed through a glass prism. Before the light reaches the prism, all of the wavelengths of color travel together even though the waves are different sizes. The prism has the effect of causing the white light to refract, separating each wavelength from the other, creating a spectrum.

Okay, that’s a lot, right? The most important thing to remember is that white light is really inclusive of a full spectrum of light.

Now, how does that apple at the top of the page appear so red to us? It has to do with the molecular structure of the apple itself. What is really going on with that apple is this; when the white light hits the surface of the apple, all of the spectral colors are being absorbed by the surface EXCEPT for the longest red wavelengths, which are being reflected by the surface – and thus appearing to our eye as RED.
 


Snap2Objects.com


The color we see is really a visual effect caused by the spectral composition of the light source reflected by an object. That’s really it – if you’re favorite sweater is blue, it’s blue because the molecular composition of the sweater is absorbing all the red, orange, yellow, green and violet waves of color, but is reflecting the blue waves.

And last but not least, as light sources change, the color of an object can appear to change as well. Like leaving the house after getting dressed in the early morning by incandescent light thinking both your socks were black, and then realizing in the bright light of day that one is actually brown, and the other is navy blue!

Of course, this is just the beginning! In the next post we’ll look at how your hardware (eyes) and software (brain) work together to process the color we see.

But here’s some things to think about, notice, and play with until then:


·        Visit a local science center or teacher’s store and spend a few bucks on a prism – and play with it. Try it with sunlight, try it with a flash light, try it with all kinds of light and see what happens.

·        Find a small piece of white cardstock and carry it around with you for a few days – and really look at it under different sources of light. Does it really look like the same “white” in sunlight, under incandescent light, and under fluorescent light? Do you notice any differences in color or “feel” from different light sources throughout your day?

·        Pick a few different colored objects, some bright colors and some dull. Look at them in the bright sunlight and think about what color each appears to be. Look at them also in fading sunlight at the end of the day – what color do they each appear to be now? And what about in a dark room with one very dim light?

·        When you find a color popping out to you during your day – like the bright red of a cardinal at the birdfeeder, or a superman blue car, or a bright white cloud in the sky – take a moment to think about the light illuminating that object. Is the light source the sun, or something else? Is it direct, bright light – or indirect light? Are there many lights, or is the object itself projecting light?