October 16, 2007
The impact of color on the art of photography famously is enormously enormous. We live in a color filled world, so we shoot in color. It’s got to look real – right? So we think. Color can accentuate a mood. So we romantically believe. Colors are pretty. Of course they are. Eventually we realize things aren’t that simple. Colors are not real.
For starters, take Picasso’s blue, rose and monochrome periods or van Gogh’s wildly yellow sunflowers. Nothing real about them but masterpieces nevertheless. Or what about something as mundane as food photography with its color distortions making us hungry. Then, shooting in black&white is another extreme form of color manipulation. What about gray granite sculptures or the white marble ones? Many of Rembrandt’s works are relatively dark toned compared to the vivid colors of Paul Klee or the light water colors of Carl Larsson.
Colors have nicknames. The 2008 Toyota Solara comes in Blizzard Pearl, Ivory, Dark Stone, Dark Charcoal, Classic Silver, Magnetic Gray, Absolutely Red, Cosmic Blue and Blue Streak. Does that stand for Blue, Red, Gray and White? Are Yellow, Green and Black no longer in fashion? On the other hand, the specs of Honda’s HR Series HRS216ODA lawn mower leave colors alone – apparently still following the Model T marketing strategy. John Deere’s 770D Motor Grader specs do not mention colors either but seem to come with tinted windows. But your bed sheets may be Ecru, Cameo Pink or Cinnabar colored.
Speaking of fashion, how about this: “Layers of haze, clouds, water and air create delicate variations of non colours next to white. Those tints are diffuse and innocent, with an iridescent shale tint contrasting the fragility of those diaphanous and bleached pastels.” Or: “In a season moving away from the bling, cheerful brights work as accents invigorating the season’s harmonious and subdued colour mood. Midtone lilacs, greens and blues compliment zesty red, orange, yellow and cyclamen”. Huh?
Some of us like pink cars, Pink Floyd and Pink Gins. Australia, Oregon and Jamaica have Blue Mountains, Bavarian forests are Black. In the 1950s, some men preferred blondes. The Irish favor green. Some US states are blue and others are red. There are Red Necks, White Trash and Blue Blooded Aristocrats. We used to have the Red Menace and the Yellow Peril. Today, we have Green Parties, Greenpeace and Glitzy Copper lipsticks. Scarlett O’Hara did history as did Jerry Brown, Red Skelton, Rosie McDonald, Karen Black and Goldie Hawn. Let’s not forget Rosie the Riveter, the Red Baron and The Scarlet Pimpernel.
Colors are just energy things that vibrate. Lots of other things vibrate without us paying attention. What’s so special about colors? There are vibrating beds but we rarely name our kids after them. In fact, the world around us is filled with vibrations of various kinds. Some of those vibrations have been vibrating for billions of years. Do we care? Still, we have an endless curiosity about colors.
There were Black Panthers, Black September and Red Armies. White means marriage to some, funeral to others and Racial Supremacy to a few. Color Racism remains alive. There were the Dark Ages, the Age of Enlightenment, the Bronze Age, Black Death and Yellow Fever. Khmer Rouge murdered millions. How about Grey Eminencies, Dark Princes, White Princes, Kingdoms of Light, Red Cardinals, White Knights, Old Blue Eye, Red Communists and Hitler Brown and Black Shirts.
Some like blue movies or head for Red Light districts or Moulin Rouge. Others prefer Yellow Submarines. We have the Redskins, pink panthers, the Whitesocks, not to mention the pink and white elephants we occasionally chase. Off Color Jokes are frowned upon. It was a dark and stormy night. We are afraid of the darkness and of white sharks. Some worship the Sun and its light. Some days we are blue. Others, we are black, pink or maybe red. We eat Brownies, White, Red or Yellow Potatoes , Green, Red or White Onions, Red Beans, Red , White, or Dark Meats and Red Hot Chili. Some wear White Shoes in the Summer, Black after Labor Day – perhaps they dress in Black for Dinner.
It’s all fantasy. We let colors symbolize ideas and feelings where we largely make up the connections. Then we can’t agree on what those connections are. Asian connections and perceptions differ from those of the Western Word. In America and elsewhere, the perception of color vary significantly depending on you skin color.
We watch Men in Black, A Clockwork Orange, Blue Lagoon, Black Orpheus, White Christmas, The Color Purple, Red Shoes, A Red Violin, The Hunt for Red October and GoldenEye. We listen to Paint it Black, Brown Eyed Girl, I’m Blue, Purple Haze, Blue Monday, Black and White, Little Pink Houses and Pale Blue Eyes. We read Devil In A Blue Dress, Blue Light, Blinking Red Light, The Red Moon and Wearing Purple. Gershwin had his Rhapsody in Blue, Miles Davis was Kind of Blue, Ellington composed A Black and Tan Fantasy, Mood Indigo and the Black, Brown and Beige Concerts, not to mention Diminuendo and Crescendo in Blue.
It’s all in our minds and nothing is what it seems. Contrary to reality and reason, colors have powerful connections to our minds. The thing is colors aren’t real. Artistically we distort them for, well, artistic reasons. Photoshop rules. We invert, bend, mix, translate, multiply, XOR and erase colors, having great fun. Why not? Perhaps we don’t understand that all we do is fool around with light beams and particles vibrating at various frequencies and amplitudes. Then we might even see that colors aren’t real. We just think they are.
Consider the simple color wheel above. Those colors aren’t real. They are the result of preparing the surface of paper, or in our case, manipulating a computer monitor. In the case of paper, you coat the surface with stuff that reflects electromagnetic waves at different wave lengths and amplitudes. In the case of a monitor, all you do is watch transistors going off and on, or seeing light guns fire away at a metal screen with little holes in it. Either way, it’s just frequencies and amplitudes.
Mother Nature is the most powerful manipulator of us all. Light and color is under constant attack. Dark colors dominate at night, while mysteriously it is light during the day. How so? Consider colors during a thunder storm versus colors on the beach or in Shanghai on a bad day. Climb to the top of Earth or dive deep into the oceans. How come the colors are so different?
Then we have ourselves and our poorly understood human perceptions of color. Our brains play a real trick on us. They make us believe that colors are real. They have found ways to generate brain waves in response to mere vibrations. They try to fool us into believing that things have colors. Things do not have colors. It’s just energy trying to be something more.
This post is largely an extract from my big essay on photography “On Reality 6: Mysteries of Photography“. Parts of the discussions update and expand the content of other previous posts, notably On Reality – Part 1 – Elements of Light and On Reality – Part 5 – How Perceptions and Illusions destroy Reality. Other posts include On Photography – Trick and Treat of Light and On Reality 6 Rev. – Jeff Wall Magic Revisited.
A Bit of Theory
Light is characterized by three components: amplitude (intensity or brightness), frequency or wave length which relates to color and polarization (angle, vibration, reflection). Light may come in the form of a beam emitted from a light source. If the beam is aimed straight at you, it is visible as a point of bright light. From the side, that beam is not visible till it is scattered into a spectrum of different wave lengths. Our retinas and brains map the spectrum of wave lengths to perceived colors.
I’m sure you have seen the standard graphs of wave length and associated colors. It goes like this: the lowest wave lengths are associated with sound as heard by humans. AM radio, TV and FM waves are next up in frequency (lower in wave length), followed by kitchen, radar and signal transmitting micro waves.
Then comes infrared light which is associated with heat – the burning logs in your fireplace emit infrared “heat”. The TV remote uses infrared waves. So far nothing is visible to us. A very narrow band of visible light, split into colors, follows. This spectrum goes from red, yellow, green, blue and magenta to violet.
After the band of colors, we return to invisibility: ultraviolet light causes sunburn. It can’t be seen by humans but is visible to bumblebees. UV light is real important in astronomy – distant galaxies and stars often only emit UV light so the Hubble telescope and some satellites are very sensitive to such light. Then X-rays follow. Finally, gamma radiation can kill, very important both to space travel and astrology.
Have you noticed I sometimes talk about frequencies and wave lengths as in an analog beam (scattered or not) and sometimes about light consisting of particles bouncing around in some pattern? Both ways to look at light are correct but how light consists of both waves and particles is a bit mysterious. An issue of quantum physics, debated by many from Isaac Newton to Albert Einstein, this unresolved subject is a bit beyond this essay.
But think about it: why would an electromagnetic pulse (light beam) be split or scattered by an atmospheric particle unless it too is a particle? On the other hand, are our eyes really letting in all these dirty particles that have traveled space and bounced off all kinds of pollution? I’d hope not. How do light particles penetrate a camera lens? This mystery will remain unsolved in this essay (as it is in science).
Colors from Happiness to Madness
So much for theory – electromagnetic waves, infrared this and gamma that, particles, amplitudes…. Let’s switch tack a bit. Visions are emotionally driven, inner convictions. Colors, in psychology, not to mention advertising and web design, associate freely with emotions. I’m blue today. He was red hot. She was green with envy. Here is one opinion (of many) on how colors associate with emotions:
- Red is the color of fire and blood, so it is associated with energy, war, danger, strength, power, determination as well as passion, desire, and love. Red is a very emotionally intense color. It enhances human metabolism, increases respiration rate, and raises blood pressure. It has very high visibility, which is why stop signs, stoplights, and fire equipment are usually painted red. In heraldry, red is used to indicate courage. It is a color found in many national flags.
- Orange combines the energy of red and the happiness of yellow. It is associated with joy, sunshine, and the tropics. Orange represents enthusiasm, fascination, happiness, creativity, determination, attraction, success, encouragement, and stimulation. To the human eye, orange is a very hot color, so it gives the sensation of heat. Nevertheless, orange is not as aggressive as red.
- Yellow is the color of sunshine. It’s associated with joy, happiness, intellect, and energy. Yellow produces a warming effect, arouses cheerfulness, stimulates mental activity, and generates muscle energy. Yellow is often associated with food. Bright, pure yellow is an attention getter, which is the reason taxicabs are painted this color.
- Green is the color of nature. It symbolizes growth, harmony, freshness, and fertility. Green has strong emotional correspondence with safety. Dark green is also commonly associated with money. Green has great healing power. It is the most restful color for the human eye; it can improve vision. Green suggests stability and endurance.
- Blue is the color of the sky and sea. It is often associated with depth and stability. It symbolizes trust, loyalty, wisdom, confidence, intelligence, faith, truth, and heaven. Blue is considered beneficial to the mind and body. It slows human metabolism and produces a calming effect. Blue is strongly associated with tranquility and calmness. In heraldry, blue is used to symbolize piety and sincerity.
- Purple combines the stability of blue and the energy of red. Purple is associated with royalty. It symbolizes power, nobility, luxury, and ambition. It conveys wealth and extravagance. Purple is associated with wisdom, dignity, independence, creativity, mystery, and magic. According to surveys, almost 75 percent of pre-adolescent children prefer purple to all other colors. Purple is a very rare color in nature; some people consider it to be artificial.
- White is associated with light, goodness, innocence, purity, and virginity. It is considered to be the color of perfection. White means safety, purity, and cleanliness. As opposed to black, white usually has a positive connotation. White can represent a successful beginning. In heraldry, white depicts faith and purity.
- Black is associated with power, elegance, formality, death, evil, and mystery. Black is a mysterious color associated with fear and the unknown (black holes). It usually has a negative connotation (blacklist, black humor, ‘black death’). Black denotes strength and authority; it is considered to be a very formal, elegant, and prestigious color (black tie, black Mercedes). In heraldry, black is the symbol of grief.
Some claim colors guide our lives in a sublime mix of emotions and realities. Personally, I’m not so sure. I believe we all are more complex than that. Form, harmony and discord, for instance, seem important as well. Probably context, such as being fired, getting married, suffering from depression or winning the lottery, emotionally overrides any color setting. Colors as emotional impacts are nevertheless legitimate parts of the magical toolbox but not at the exclusion of other factors.
Unreal World Color
AA Gills of the London Times recently visited Tasmania and filed the following observation (italics mine). Rarely have I seen so many unusual wave lengths covered in so few sentences:
- The rocky shore is tortured into a macabre and dramatic beauty. The waves stand up on their hind legs and lunge at the land, to be flayed into bone-white shreds by the black rocks. In the late afternoon, the sky is glowing pale gold, dark mauve clouds are filigreed pink, thousand of mutton birds (sheerwaters) fly low over the silver water, and we hurry back in the teeth of the wind to our hut.
Now, that is the drama of colors, if somewhat tortured. I’m sure Conrad had not been able to put it better. AA Gills actually is a restaurant critic and feature writer for the Times but seems to have his hands in plenty of pots. Good for him.
Take that sun beam traveling through space towards you. At high noon, that beam will hit the atmosphere straight on. Since the atmospheric particles are much larger than those associated with the beam, the beam is scattered into predominately short wave lengths – blue. Thus the sky is blue during the day. As the sun sets, the angle of the sun beam is to close to 90 degrees. Now we see more of the longer wave lengths – red.
Colors depend on altitude – the higher you are the bluer the scene and the sharper the shadows. A higher altitude means, mostly, less pollution and more unhealthy radiation from space ranging from UV to gamma energy. Sun beams are less scattered, hence the scene is lighter. There are fewer clouds if you go high enough. Perhaps you are high enough to encounter snow which reflects enormous amounts of light. Or, returning to zero altitude – sea level – you better consider a similar high reflection of light from the sea surface. In this case, polarization becomes yet another tool. Keep this in mind next time you climb Mount Everest.
As a side line consider Global Warming. Color, together with light in general, plays a powerful part. As temperatures go up due to CO2 content in the atmosphere trapping the Sun’s energy – some in the form of ordinary light – ice packs melt, the ground becomes darker, reflecting less energy back into space, making temperatures increase even faster in an evil circle that may be unstoppable at some point. Simple color properties may extinct mankind. Perhaps.
The color spectrum varies tremendously from one location to the next. You have monochrome environments such as deserts, ski slopes, some beaches, polar ice areas, tundra, oceans, mines and tunnels. Next, there are monochromes with occasional color items, such as many parts of an inner city or fireworks. Low light photography is usually close to monochrome, wherever you are. Intensive colors are found in many tropical locations. Specific places such as the Dutch tulip fields in the right season or Brazilian Samba festivals are colorful. You choose your film or white balance (or other settings) with that in mind.
Colors Ain’t Colors
Colors aren’t real. They simply are associated by your brain with light particles vibrating at certain frequencies. As humans, color processing follows a complex path through the eyes, to the retina with its three basic sensors (blue, bluish-green and yellow-green of all odd compositions) and on to the brain, where it is all sorted out according to a set of rules. A given wave length is translated into a “color”.
Put an 80A blue filter on your lens (or simply look through it) and colors change. This particular filter changes light emitted from reddish tungsten sources back to “normal” daylight color spectra, given daylight film or white balance. Here is what actually happens: the filter is manufactured so it absorbs vibrations in the 1800-2500K range (perceived as red) while letting the shorter wave lengths through. The result of applying the filter is that the scene appears to emit relatively more short wave length rays, correcting for the excess emission of light in the 2800K range typical of tungsten light. It’s all a matter of wave lengths, not “colors”.
Walk into a color darkroom and twist the color correction dials a bit and the color print comes out quite differently. Play with color settings in Photoshop and the image changes accordingly. Put on your sunglasses and colors shift. Color blindness changes how wave lengths are mapped in your brain due to some part of the system being damaged. Several other deficiencies change our perceptions of color. Colors are what you make them to be.
Next, we need to represent color in print. Now we deal with a totally new set of representations. CMYK (cyan, magenta, yellow, black) is the traditional print representation which has absolutely nothing to do with how we humans perceive or process color. Pantone’s system of six colors for increased precision adds orange and green to the CMYK system. So we invent these systems of classifying colors. All that actually happens is that various materials with different light energy scattering properties are applied to a piece of paper.
Do Computers See Colors?
Computers use their own concepts of color representation. Colors are associated with an RGB (Red, Green and Blue) model. This model assigns trios of numbers from 0 to 255 to the “colors”. Red, for instance is coded as (255,0,0) and blue is (0,0,255). (0,0,0) means black, (255,255,255) stands for white. These numbers are used not only to describe colors internally but also to control the electron gun of an analog monitor or the transistors in flat screen monitors.
The RGB model does not actually represent real colors but are simply some numbers that could represent anything or nothing. The numbers do not automatically result in accurate colors. The computer and the monitor need to be told what an “accurate” color is. This information is held in one or more arrays that say “apply this correction when sending info to the monitor or printer”. You are responsible for keeping those arrays up to date, using available tools. Many of us don’t do that and hence get used to strange colors and fail to understand why others complain.
Monitor color guns or color sensitive “dots” must also be carefully calibrated to some standard color space. Such calibration uses elaborate color management tools. The standard monitor color spaces come in many flavors of RGB (red, green, blue): sRGB, Apple RGB, Adobe RGB and ColorMatch RGB. On the printing side (CMYK), we have a set of US standards together with corresponding (different) European and Japanese variations.
A simple but crucial monitor setting is the brightness, referred to as the “gamma” setting. Just for fun, Apple uses a different gamma standard than PCs. A Mac calibrated image looks darker on a calibrated PC and vice versa. Great, isn’t it?
It’s not over yet. Next is the coordination of color spaces and calibration across devices. The digital camera, the scanner, the monitor and printing using external labs or the onsite photo printer must be calibrated accurately to compatible color spaces. This is not a trivial undertaking although special software may reduce the pain a bit.
Computers have no understanding of colors – to them it is just a numbers game. Perhaps by now you wonder in what way all these classifications, standards, rules, adjustments and measurements are relevant. Nature itself makes far greater adjustments without blushing or asking for permission.
Colors, Oh Those Damn Colors
Maybe you conclude things were simpler in the old days of taking your color film to some lab or retailer, accepting the result – perhaps grudgingly but with little chance of being heard. Heck no. In the “old days”, a good print meant endless darkroom exercises tinkering with enlarger settings, which doesn’t even start dealing with the external viewing or printing issues. Color management was not easier but merely overlooked in many cases, or more accurately, achieved in a different way.
Colors and photography are a true mess. Technology makes it all harder instead of easier. Truly managing colors in photography is a massive undertaking that many photographers avoid or ignore. The bright side is that if you make the effort to master color and its management, you are far ahead of much of the competition. The bleak side is the hours you spend on tinkering with calibrations, devices and standards. Many of us end up with a compromise. One compromise is to let specialists deal with the whole issue. That is expensive. Another option is to wing it. You learn what makes a nice print on a trial and error basis. You learn that a bluish tint on the monitor results in a great print on your Canon printer. And you get on with life.
Let’s jump into yet another issue. Different films as well as different digital chips have unique sensitivities to the wave lengths of color. A particular film (or sensor), black&white or color, may be more sensitive to blue than red. Another film or sensor may behave in the opposite manner. Each film is associated with a sensitivity profile ranging over the wave length spectrum. This spectrum sets the film apart from other films. The same is true for sensor chips in a digital camera. The difference is that the chip is permanently in place while, in the film case, you can simply change films to match the shooting situation and your vision. The back end (film or chip) may be sensitive to waves beyond the visible spectrum. In the case of film, that may be X-ray waves.
The latest Leica M camera, the first digital version, suffered (suffers?) from an abnormal sensitivity to infrared light. This resulted in strange distortions that were visible in the images under some circumstances. Given a price of around $4,500 for just the camera body, that is a bit embarrassing. Is it a unique case? I think not.
Now you know one major reason I love black&white photography. Not that any of the color issues magically disappear (they surely don’t since you have to manage the color to gray scale transition) but dealing with a gray scale is a lot more natural to me than tinkering endlessly with scores of color standards. And in my mind, b&w has an artistic impact unmatched in any medium. That, of course, is just my view.
Using Color: The Magical Toolbox
Color work splits into two events: Before Exposure and After Exposure. Colors are only a form of light or, precisely, they come from light beams split into color waves. Everything in the previous section about light applies to color waves as well. This section expands on the special form of light referred to as colors.
The Before Exposure considerations include:
You have an artistic vision. You developed a photographic style. You are on assignment. Let’s say you’ll shoot color. The first consideration is that your vision most likely favors certain color combinations, mood and overall light. It may be in-your-face harsh light and strong, exaggerated colors. Or perhaps it is calm muted colors with a minimum of shadows. It might be a mix of the two. Next, mesh that vision with the requirements for the shoot (if any). The vision rules, the requirements are the handcuffs.
Then, find the location that matches the vision and requirements. You are, of course, familiar with all the ways in which colors and light vary depending on a great many, but often predictable factors (excluding weather in the case of outdoors shoots – if you need sunshine and it’s raining hard, you’re out of luck).
Now you have advanced to the chosen location. It is a matter of setting up the actual shoot. The dominating consideration still is color and light. Even with the most informed choice of location, there will be color and light issues to deal with. Things are always just a bit out of sync. Sometimes they are way out of sync. The exception, of course, is if you maintain your own control over light and color by supplying you own lighting setup. Jeff Wall can spend weeks or months waiting for light and colors to be just right.
Your vision, of course, favors certain compositional elements, including color preferences and associated moods and balances. Now faced with the real world, perhaps the scene does not match the vision perfectly or, maybe, not at all. It is time to reconsider and improvise. Or walk away which might be costly.
So a particular dance starts up, similar to the “As Time Goes By Can Can” already mentioned for exposure and composition. Let’s call this dance “The High Noon Two Step”. You run around the location, checking out shadows, highlights, midtones, light ratios and color shifts, perhaps wishing you were free to move around the country instead. You’re adjusting this and moving that. You tinker with the camera, fitting filters, changing film, moving the white balance this way, then that way. You’re pre visualizing like a mad man. You snapping test shots left, right, up, down and possibly upside down.
Eventually, you have to admit you used all the tools and excuses, the scene is OK and it’s time to actually start shooting. The madness actually followed a path (although no one else may believe it). So the “As Time Goes By Can Can” compositional dance is about to start. The color work is temporarily on hold. Actual pictures are about to happen.
After Exposure, there are more opportunities to screw up or to enhance the images:
Development strategy or initial Photoshop corrections: You did, of course, pre visualize the image which should define the steps to take in development and printing. But sometimes the initial result isn’t quite what you expected. Maybe your white balance setting was a bit off. Perhaps the color film wasn’t quite to specs or the development chemicals a bit too old. So don’t be too surprised you have to apply some initial corrections to get the colors back on the intended track.
Alter the color balance and related features: Your pre visualization may well include corrections to the original image. Perhaps you shoot digitally but the plan is for a black&white image. Maybe you planned to enhance the original image to fit into your vision or work spec: apply more vivid or muted colors, shift the colors to some off beat point, add some special effect or combine several images. There are literally infinite possibilities to make your vision come true, whatever it is.
End use adjustments: Most likely the image has to be adjusted fit the particular color (and other) requirements of the intended end market, be it a photo album, web site, print advertisement, gallery show, museum purchase or a shoe box. Each end-use has different requirements, usually radically different: the color capabilities of the web are very different from an offset printer as an example. Typically, your image must be adjusted into several versions: perhaps one to show to clients in your carry-around portfolio, one for your web site portfolio, one for your long term hard drive storage, one containing your printing instructions, another for off-site printing, low resolution versions for Flickr, MySpace and the hundreds of other promotional web sites.
The final image and follow ups: You’ll produce the actual high resolution image in all its glorious colors to be used, published, shown or exhibited. Hopefully you’ll reap the well deserved rewards. Then you’ll consider documenting and protecting all the color (and other) work you have put into not just this image but the perhaps thousands of other images in your portfolio. This is a real management issue – how do you keep track of all these versions of a single image and all its unique settings for different purposes? Especially considering you own thousands of images? How do you keep them safe over long periods of time? How do you record color (and other) settings so you can repeat them? There are many solutions available – I’ll have to leave that part to you.
That’s it for the discussion of colors. Together with the light discussion, you have a pretty good foundation for dealing with these two critical elements. The idea was to alert you to some of the intricate details of these basic components of your magical toolbox. Next, we’ll examine the two other fundamental components. That is the camera with its lenses and backends followed by the human system of eyes, retinas and the brain in processing the images.
October 2, 2007
Photography is a dangerously gadget friendly environment. Stocked with hundreds of cool camera bodies, lenses and miscellaneous equipment, camera stores happily sell thousands of accessories. Add chemicals, development materials, printing accessories, computers, memory cards, special monitors and you end up with an empty wallet and far more headaches than you deserve. Or as some partners put it, all those headaches you do deserve. Often stated, boating is a hole in the water into which you throw money. Photography is a hole in the sky into which you throw not only money but perhaps your marriage, career, cat and sanity.
The first camera I used was one I liberated from my father. Equipped with a bellowed fixed lens, zero batteries and no focusing assistance, it sure was a curious little machine. Using medium format film in a body smaller than a Leica rangefinder, it took remarkable photos. Not only that, the absence of any modern convenience resulted in complete freedom from gadgets. In fact, available accessories numbered exactly zero. Those were the days.
The basic idea here is that gadgets don’t make photographs – not bad nor good ones. Photography is made possible by light. Light is preserved and eventually becomes viewable as a photograph. No gadget ever changed this basic notion. Light is about photography and photography is about light.
This post is largely an extract from my big essay on photography “On Reality 6: Mysteries of Photography“. Parts of the discussions update and expand the content of other previous posts, notably On Reality – Part 1 – Elements of Light and On Reality – Part 5 – How Perceptions and Illusions destroy Reality.
Light is not a simple matter. Here are some of the theories dealing with light: Optics, Particles, Waves, Magnetics, Electrics, Relativity, Quantum, Wave-Particle, Electrodynamics, Radiation, Radiation and Light Pressure, Spectral, Ballistics, Photometry, Spectrometry, Lasers and much more. Yet the basic idea isn’t that complex.
Light is energy. This energy is emitted by sources such as the sun. Light energy consists of magnetic and electric waves traveling through space, atmosphere and some other media. The human eyes are sensitive to light waves. Our brains interpret the light energy as representing the world around us. A photograph captures the light present in a particular moment in time.
Nothing is more important to a photographer than light. No light, no photography. As a photographer, you must love light. You better love how light bends, creates color, enters a lens, refracts, reflects, bounces, scatters, disappears, enters eyes for processing in the brain and how it is affected by sun spots, black holes, cosmic rays, global warming, atmosphere, clouds, rain, weather, pollution, dust and much else.
All of the factors above are distortions. The original light source, the sun for most practical purposes emits “pure” light. By the time that light reaches some place on Earth and your camera lens or eyes, it is very different compared to that original “pure” light. Light from space is distorted even before it reaches our atmosphere. Then the atmosphere adds its set of oddities. The camera is a virtual snake pit of distortions. Manmade light adds other distortions – its light is differently colored than the “norm”. Our eyes and brains add more layers of distortions.
In the beginning, people assumed one saw by emitting light beams out of one’s eyes. Pythagoras, 500 BC, assumed light traveled from the eyes and a sensation of seeing followed as the beam hit some object. Plato, 400BC, supported the same theory. Around 300BC, Euclid questioned that eyes were the only source of light and formulated quite a bit of light related mathematics. Still, the view of the eyes beaming light prevailed. The Bible mentioned “And God said, let there be light, and there was light”, associating light versus darkness as a good versus evil issue.
Around 1000AD, al-Haytham of Egypt finally voiced the idea that light entered the eyes rather than the other way around. He concluded the sun was the source of light. He also invented the Camera Obscura although Leonardo da Vinci received some of that credit 500 years later. Unfortunately, our gentleman resided in jail, so his findings were not immediately available. Most of his ideas were based on the sun light coming into his cell through a tiny opening or crack.
It took over 500 years before al-Haytham’s theories reached Europe, inspiring Kepler to formulate some fairly correct theories late in the 1500s. Galileo, Descartes and Newton added tremendously to the understanding of light over the next 100 years. The wave theory came along through Euler in the mid 1700s. Other contributors include Fresnel, Poisson, Faraway, Planck and Maxwell, leading up to the late 1800s and pretty much the way we understand light today.
A Simple Theory of Light
Light is produced by light emitters, reflected by certain objects and consumed by others. Light is radiation energy affected by combinations of photons, atoms, molecules and other low lives. It has characteristics such as wave length, frequency and intensity, all of which vary tremendously with quite spectacular results. Most light originates at the sun and manmade processes. Light may be a single beam or scattered in a collision with some obscure molecules.
Radiation is a form of energy with intensity and wave length, vibrating around us constantly. Low frequency waves represent sound. There are TV and radio waves, visible and invisible light, radar waves, cellular phone radiations and X-ray emissions. Light as we see it and as used by a camera is only a small part of the energy waves around us. In some cases, invisible wave lengths affect film or memory cards in undesirable ways. Don’t X-ray your films. A rather extreme example is the HEMP bomb that can fry all electronics within a large radius; including your camera (unless you use a camera similar to that of my father, but even so, the film is probably a goner).
Light is created in many ways – the sun maintains a controlled nuclear explosion emitting lots of radiation energy, some in the form of light, other in the form of quite deadly variations such as gamma rays. Light bulbs, neon lights and many other manmade devices emit light on demand. Such light is usually created by the combination of energy in an enclosure containing suitable gases. Other light sources include computer, radar and TV screens which operate using cathode rays and energy sensitive coatings or by turning transistors off and on. Nuclear reactions produce lots of radiation, some of which is visible.
Heat generates light; increasingly hot temperatures transform light from the original color to a glow of red, white and eventually blue – think about your stove, fireplace, kerosene lamp or volcanic lava. Military night sights use slight heat variations as emitted in the infrared spectrum to “see” a battle field. Chemical processes generate light in some organisms: fireflies, glow worms, krill and others. Lightning produces a short burst of light based on heat.
When light falls on an object, some waves with a specific length are reflected and others absorbed. Light emitted by an object also have a specific set of wave lengths. We perceive the light of a specific wave length as a color. We thus “see” the object having a color. The reflected light is not a constant since it depends of the wave lengths of the incoming light. Reddish sunset light makes any object look reddish while the same object is bluish at noon.
Photographers and light meter manufacturers make a big deal out of incident and reflected light. Incident light measures incoming light only and then make assumptions about correct exposure. Reflected readings do the same for reflected light. The problem is that different object reflect light very differently – snow, water and any light object reflects much more light than dark soil, a black cat or any dark object. That means that neither incident nor reflected light measures result in a correct exposure. In the case of snow, an incidence measure will overexpose the scene while a reflected metering will underexpose the same scene. The only time you get a good measure is when the scene is a uniform 18% grey – a very rare occurrence.
Auto exposure cameras use only reflected light as does the Zone System. Popularized by Ansel Adams, the Zone System attempts to correct the ambiguity in light measures. In fact, that is the major point of the Zone System.
Meanwhile, the auto exposure camera relies on you to override its automatics to produce a correct reading. Nothing automatic about that, is it?
Most objects are not producing light at all. They are only visible because they reflect light. A chair does not normally emit light. The moon does not produce light – it solely reflects light mostly from the sun. There is a bit of a fallacy here because heat produces light. Heat the chair up and it will produce light. Humans do not produce light but we (and animals) have a body temperature that does cause light emissions in the invisible infrared spectrum. If we actually turned into visible light emitters we are very dead because that implies heat sufficient to make us glow red – blue – white. That would not be healthy. However, it is possible to photograph people in total darkness. All you need is a readily available sensor or film sensitive to infrared light.
Light intensity declines rapidly with distance. Most photographers use a simple formula stating: double the distance from a light source and the intensity is down to a 1/4 of the original intensity. That is an approximation that serves photography well in most circumstances but is actually wildly inaccurate. If you get close to a light source, then light intensity to distance is almost flat regardless of distance. Nor does the rule hold up when the light is focused with some sort of reflector as you may have noticed using a flashlight, driving at night or watching the beam from a lighthouse.
Light never dies. As time goes by and the light travels great distances, the intensity goes down but it never reaches zero. We are surrounded by light originating billions of years ago. Unfortunately, the intensity is way down making it impossible to see for us humans. The Hubble telescope is extremely light sensitive and can pick up very distant light originating a long time ago.
There is no such thing as “seeing” an object; our eyes only receive light emitted and reflected by the object. The light waves reaching our eyes are quite distorted. The eyes introduce more distortions due to various imperfections. The brain then makes up a “view” of the object, introducing additional distortions. The brain is easily fooled into providing false or biased views. What we “see” is not an accurate representation of the object, it merely is one deemed safe by our brain.
Light Traveling Space
The sun is our major source of light. This light is comes from a massive nuclear reaction that has been going on for billions of years. Sun light affects human health and climates. The current Global Warming crisis is caused by sun energy being trapped by CO2 concentrations rather than reflected back into space, which causes temperatures to rise to dangerous levels. Sun light produces Vitamin D and fuels millions of energy requirements. It also causes skin cancers and ultraviolet radiation aging us. The sun will very certainly cause the demise of mankind, possibly through Global Warming but for sure as its energy runs out.
Stars, clusters, galaxies and nebulae provide some light. Polar lights (Aurorae) are clearly visible in high latitude areas and seasons. The moon reflects sun light. Magnetic fields in space bend light, space storms distort light, black holes does who knows what with light and sun flares send out a lot of unpredictable and usually harmful energy.
Cosmic “rays” refer to Earth being bombarded by energy containing particles. These particles originate with the sun but also exploding stars, novae, galaxies, quasars and black holes. These generally low energy (unless you are an astronaut) particles have some limited effect on climate by affecting lightning and cloud formation. Solar cosmic rays can affect electronics on Earth such as communication devices and possibly digital cameras. Then there is the Oh-My-God particle (really) traveling around the Universe at extreme speed and containing enormous energy, given its tiny size. But that is another story.
Photography in space is quite different than on earth. The radiation levels are harmful to film. NASA tests film extensively to reduce fogging and color shifts – they tend to use film specially made for them by Kodak. Today I’m sure they use digital cameras with similar quality considerations.
Light in space is either on or off with photography taking place when light is on. With the light is on, it is very constant – no clouds, haze, rain storms or shadow. There are only two basic shooting scenarios: close or far. Shooting earth from the space station means using one standard exposure (reflected light is quite constant) and the lens set at infinity. Shooting “close ups” such as space walks require a similar standard exposure and some focusing. Photography inside the space vessel is similar to that on earth.
Space light is much bluer than on earth. There is far more ultraviolet radiation which is not visible with eyes but may impact images. Contrast ranges are extreme – consider an astronaut in a white suit against a pitch black background. The seasoned space photographer must also consider speed. Everything moves way faster than earth speed limits. The shuttle moves at 17,500 miles an hour (5 miles per second or 110 feet a typical exposure of 1/240 seconds) so panning is a necessary skill. The Cartier-Bresson Decisive Moment takes on a different meaning. In space, a photograph doesn’t freeze a moment in time. It records a sequence of movement
Atmosphere and Time
The atmosphere greatly impacts light from space. Distortions include seasonality, clouds, storms, humidity, dust, pollution, inversion layers, refractions and reflections. Other factors include time of day effects and temperature distortions.
When light beams reach the atmosphere, they scatter as they collide with atmospheric particles. During the day, this results in a blue sky because the light is coming from a high angle. In the early morning and evening with a low sun, we see a reddish sky because the angle of the incoming beams is low. Without clouds, we experience a mix of sun beams and scattered light. Snow, water and beach sand reflect light more than dark objects. That elevated light level reaches your camera and confuses the light meter. You better reduce the exposure. Ice also reflects light but amplifies the blue wave lengths. Thus, photos of ice bergs usually have a deep bluish tint.
Seasons display unique light effects. Snowy landscapes require special attention to exposure. Fall foil colors can overwhelm a landscape. Some enjoy the Christmas feeling and warm toned nostalgia. Seasonal sports and graduations are popular events. Some regions suffer extreme weather seasons such as the Arctic winter, the hurricane plagued Southeast US coasts, the mid US Tornado Alley and the Asian Monsoon and Cyclone season.
Clouds reflect the direct sun beams and all we see is the scattered light waves – shadows disappear or dilute. The water content of the clouds scatter light in a way that produces no particular color, hence the grayish feel with a complete cloud cover. The thicker the cloud, the less light passes through. Extreme weather can lead to almost total darkness and a general loss in color. The red rose is suddenly grey.
Bounces and Refractions
Refraction of light is the bending effect that happens when light passes through certain media at certain angles. The straw in a glass of water is the classic example. Refraction is, for instance, the cause of rainbows. The atmosphere provides refraction of sun beams: the lower the sun, the more the refraction. At sunset the refraction can be as much as half a degree or about one sun diameter. This explains the “oval” sun at sunset or dawn. Another effect of refraction is the “floating mountains” or “elonged islands or ships” seen on hot days (Fata Morgana). Other special effects include mirages and the common illusion of distant pools of water on hot roads. Refraction also makes it possible to see beyond the natural horizon.
Refraction in a vacuum is exactly 1.0, which means there is no refraction. The atmosphere has a refraction of 1.0003 while ordinary water refracts 1.33, quite a bit more. Acrylic glass has a refraction index of 1.49 and diamonds are at 2.42. Silicon has an index of over 4 although that probably won’t be much of a photography issue.
Refraction also is important because different wave lengths of light have slightly different refractions in different materials. This causes dispersion of the light into colors. Diamonds, for instance, are very high in dispersions causing their extraordinary “fire”. One moment you see blue light reflected from the stone, then perhaps green or pure white. Rainbows are another example of this phenomenon. Reflection, dispersion and refraction are the mechanisms by which many different kinds of prisms work – very important design aspects of your camera’s lenses.
Pollution and Dust
Atmospheric pollution affects light. Compare light in a smogged Los Angeles, Mexico City or Shanghai to that experienced on top of Mauna Kea in Hawaii. Broadly, there are three kinds of atmospheric pollution agents. Some reflect solar beams back out into space, resulting in less light and cooler temperatures. The sulphur dioxide crisis of the 1960s and early 1970s is a good example. Other pollutants, such as carbon dioxide, do the opposite – they allow the sun energy to pass to the surface of Earth but disallow the required reflection of excess energy back out into space. The result is Global Warming. Yet another pollutant, typically Freon, destroy the ozone layer allowing ultraviolet light through at levels threatening health.
Here are the smoggiest cities: London, New York, Los Angeles, Mexico City, Houston, Toronto, Athens, Beijing and Hong Kong. Smoggy areas include the Ruhr Area and Silicon Valley and many places in China, Southeast Asia and India. Forest slash and burn practices in Indonesia cause severe smog and smoke in much of surrounding countries. The disastrous 1952 smog in London killed 4,000 people in four days, followed by another 8,000 in the next six months. On a happier note, both LA and Mexico City have made substantial advances in controlling smog.
Apart from the health issues, heavy smog can easily make any normal photography impossible.
Dust in the atmosphere typically reflects sun energy back out and thus has a cooling effect as well as a darker sky. Sunsets tend to be tremendous. Volcanoes cause massive emissions of dust, particles and ashes into the atmosphere. The eruptions of Mount St. Helen and Mount Pinatubo spewed out ashes that traveled the world for several years. Dust storms due to drought are another major source. The Oklahoma storms of the 1930s, today’s Sahara storms and those of China affect all of Earth. Global Warming will amplify dust storms due to extreme droughts. Yet another source of particles in the air stems from forest fires due to deforestation in Brazil, Malaysia and, above all, Indonesia. The uncontrolled fires in Indonesia cause severe health problems in not only Indonesia but all of Southwest Asia. The particles circle the
Natural light is terrific to photographers. Manmade light is a pain. Hundreds of different devices, lamps, bulbs, processes, materials, gases and energy sources result in the strangest of light spectra. Add that manmade light is generally there because the natural light is not available. You are stuck with the darn thing. True, you can set up your own light version with all kinds of expensive photographic lighting devices. That’s fine but really what you do is to replace one manmade environment with another manmade environment.
K (Kelvin) values and wave spectra are important to photographers. A K value is an average of a light source’s color spectrum. A spectrum provides much more information about the scene than does the K value. For instance, the spectrum may have a high wave length peak and a low peak – a ‘U’ pattern. The K value will fall between the peaks and not really mean a thing. What you need is, perhaps, double filtration to correct for the two peaks.
The K value of sunlight is about 5,800. Typical daylight is either 5,000K or 6,500K depending on if you go for the US standard calibration or that of Europe. Computer monitors are calibrated to between 5,000K (reddish yellow) and 9,300K (bluish). Digital cameras often display white balance settings in terms of Kelvin values. In the spectrum of colors, red is around 1,800K, the average is 5,000K to 6,500K and blue starts around 12,000K continuing up to 16,000K. Examples of low Kelvin light: Match flares, candles and ordinary (tungsten) light bulbs. Here are some high Kelvin items: Xenon light, analog TVs: “the bluish flicker from you neighbor’s window”.
Unless going for abstraction, photographers compensate for the local K value/spectrum to bring the image back to “normal”. For instance, you try to make skin tones similar to those recorded in regular daylight. That may be accomplished through lens filters, white balance adjustments or post production trickery. When you do that, obviously the original scene is distorted – the ugly manmade light was, after all, the real thing.
Most fluorescent and gas discharge lamps have “interrupted spectra”, meaning the spectra are not smooth curves but a series of narrow peaks over the frequency band. Such irregular peaks, often in the yellow to green range, are very hard to filter away. The only real solution is to use alternative lighting such as flash. Gas discharge lamps include neon light and high intensity lights (mercury vapor, metal halide and sodium vapor) as used in light streets, stadiums and factories.
Then there is another issue. Film or sensors react quite differently to odd light situations than do your eyes. Your eyes and brain compensate for strange light to make it more consistent with your built in database on how a face “should” look. A camera has no such database or ability. It records incoming light according to its fixed sensitivity to different wave lengths.
Are shadows the opposite of light? Of course not, shadows are light just as is present elsewhere. They are a bit darker, that’s all. Zone system proponents know all about shadows being as important as high lights. The old film saying is: “expose for shadows, develop for high lights”. Or, in the case of digital photography, do the reverse, i.e. shoot for high lights and balance shadow detail in Photoshop.
The dynamic range of light in photography is typically measured in f stops. If the ratio of light intensity in high lights compared to minimum light is, say 1024:1, or 2 raised to the power of 10, then the range is 10 stops. There is a huge difference in the ranges different media are capable of recording or displaying. Your eyes are amazing in that not only can they cover the largest dynamic range, they also are self adjusting in real time. Other devices don’t even come close.
On a cloudy day a scene may display a dynamic range of as little as 3 stops. On a sunny day, the same scene may display a range of 12 stops. That is well within the capabilities of most eyes. Eyes can dynamically adjust to a 24 stop range although a more static range of 10-14 stops is more realistic. Most cameras (film and digital) can handle a range of about 8 stops, a considerable reduction. A typical print covers about 6 stops and a monitor slightly less. Newspapers can only display a range of 3-4 stops.
Several techniques and technologies exist to extend either the original or the displayed range. One recent example is High Dynamic Range Photography. In traditional photography, special development techniques coupled with corresponding exposures can do the trick. Consider the Hubble telescope and its ability to record and then enhance the dimmest of light.
In practical, everyday photography, the biggest factor in getting a decent dynamic range is simply to use correct exposures. Over or under exposure quickly destroys the dynamic range. One stop overexposure loses one stop of range on the high light side. Please note that correct exposure is not the same as pointing your camera at something and letting the built-in light meter (or for that matter an external meter) blurb out some numbers. Light meters are very stupid about measuring light. Practice, practice so you truly understand exposure. Otherwise, your shadows or high lights are off, were off and will stay off, blowing you out of the water every time.
Now that you know a little bit about light, how do you use that knowledge? In generic terms, the benefit of this knowledge is that you know more about what to expect. Make that an element in your photographic execution. Photography in big cities usually means polluted air which produces a different light than that on top of Mount Everest. If you shoot in an ice cave, the light is blue, while if you shoot in a sand cave, the light is reddish. Indoor shooting at, say, Christmas, will probably produce warm, reddish photos. Shooting on a lit street may produce very strange color casts.
We do not know all there is to know about light – much remains a mystery. The current knowledge is recent or no more than a hundred years old. Yet we speak of light with deep convictions, especially in photography. An image “captures” the light, a print contains the “full range” of light, the light reflected from a face “accurately” captures the skin tones. Professional critics have a language, of their own but incomprehensible to many of us, classifying and judging light and how a photographer deals with it in his art.
A photographer can use tools to analyze light. The intensity of light falling on a subject or reflected from a subject into the lens is easily measured. He/she can even determine the color of light falling on the subject. Once the picture is taken the image can be analyzed either with software in the case of digital images or by a densitometer in the case of film. That is all fine, but no meters will ever tell the full story and in fact they may even hide the real magic.
The true story about light is not one of analysis. It is about the creative use of light presented at a particular shooting event. To create that vision, you need to realize light is not just one thing. It is a combination of many different kinds of effects and distortions. Once that is clear, here are a few ideas that you might use to figure out your very own creative toolbox. A tool box is an individual treasure chest. What is a trap to some is an opportunity to others. We are all as different as are our visions. So take the following as nonexclusive ideas, not sinister laws.
- History and Theory: The history of our understanding of light is long, colorful and by no means finished. The “seeing” interaction of eyes and brain is only partially, and very recently, understood and no doubt inaccurate. Think about the significance of all those tricky images designed to fool the brain – where straight lines suddenly look bent. Or where stationary images impossibly start to move? In your fooled brain, that is.
- Space: Most natural light comes from space. As light travels through space, it undergoes transformations, most quite subtle. It bends, gets malformed, disappears, reflects, is colored and ends up differently than expected in largely a random, uncontrolled manner. Light in its “cleanest” form is quite variable even if you reside on the International Space Station. The atmosphere is then doing it’s best to make matters even more complex:
- Atmosphere: The atmosphere shields us from a quite harmful space environment. The ozone layer filters out UV radiation. Space is filled with particles harmful to humans that have come close to killing astronauts. These particles luckily do not penetrate the atmosphere. As the atmospheric filters do their work, light from space becomes even more modified. Then local conditions change light again, either by less filtering or more. A photograph taken in Australia or in Antarctica may be subject to a lot more UV light than elsewhere. A picture shot from an airplane at 37,000 feet is subject to more bombardment of essentially radioactive particles than one taken in Times Square, New York.
- Refraction: Light bends as it passes through certain media such as water or a lens. This leads to many special situations and opportunities, whether you appreciate oval suns, mirages, Fata Morgana, rainbows, floating mountains or tilting buildings. You figure it out. Make a list of the special situations created by refraction in your shooting environment.
- Reflections: We all have many so-so shots of tall buildings reflecting wobbly images from their glass walls. And those self portraits using a mirror belong deep in that shoe box in the garage. We realize how reflections from snow and water may be controlled by polarizing filters. Portrait photographers use reflectors to create a pleasing light. Film and TV crews do the same. Daylight may be modified by fill flash to create an illusion of reflections. Reflections, in any type of photography, represent huge and under used opportunities for creativity. Think about it. Create you own sun! Make your own shadows!
- Time of Day: Time of day is an essential tool. Most photographs can only be successfully shot at very specific light conditions, whether it is due to the light intensity or its color balance. Examples: Rarely is noon light the best for nature photography. Long shadows may accentuate the emotional impact of a scene. Some animals are only reachable at certain hours. Downtown traffic is busier at rush hours. Indoors, the uses of ambient light through windows depend not only on time of day but also on the angle to the sun. At noon, light from a south facing window is quite different from a window facing north.
- Seasonal: Many of us associate seasons with specific events. You shoot fall colors as leaves fall. Or delicate spring colors as leaves return. Cherry trees bloom. Whales, salmon and birds migrate. Grizzlies wake up or retire. Frozen lakes thaw. Change your wardrobe. The barbeque is manned. The car gets its annual wash. The first strawberries show up. Taste the Beaujolais Nouveau or fresh halibut. Eat your heart out at Thanksgiving. Do the Christmas shopping. Snowmobiles, motor cycles or power boats roar. Sailboats tack. Dust off the camera after its winter slumber. Wash the windows, cut the lawn. File April tax returns. Harvest the apples, wheat and oranges. Does you vision include such items and more?
- Weather: Nature gives us hurricanes, tornados, cyclones, fog, heavy rain, soft rain, clouds, thunder, lightning, sunshine, snow fall, heat waves or cold spells. The impact on your creative situation and challenge is obvious. Weather not only impacts light, it affects the range of possible or desired subjects. Some like shooting close up pictures of tornados. Most of us prefer to run like hell.
- Pollution and Dust: Imagine grabbing your camera, crawling into your bed and under the covers. Try taking a photograph of your left foot. That’s not real easy, is it? The bloody covers filter out the light. So do pollution and dust, both of which consist of airborne particles (and perhaps gases), covering earth like a blanket. Both reduce light coming through and both modify the color of light. Dramatic pictures from hazy Shanghai are perhaps interesting but not real artistic in most cases. The thing is, not all light effects are desirable in the sense they create creative opportunities. Some are simply bad news to most photographers. Here is another example:
- Manmade Light: Speaking photographically, manmade light is a pest unless specifically created for photographic purposes. Blast that sodium light. Darn that fluorescent office light. Curse those wave length peaks and valleys. Green faces, orange hair. What is fun about lobster red skin? Well, nothing much. Maybe useful in some artistic visions, manmade light is a curse to most photographers.
There you are – you have a shopping list for your magical light tool box and a list of features to think about. This discussion of possible opportunities could go on much longer. It won’t, at this moment. The main idea still is that you are the one to create your own box, preferably by thinking outside the box. Try it on. Now, let’s check out colors which are just one form of light.