Light, Color and Perception

 “If one says ‘red’ – the name of color – and there are fifty people listening, it can be expected that there will be fifty reds in their minds. And one can be sure that all these reds will be very different.” “We never really perceive what color is physically.”

(Josef Albers, American-German artist)

Jonathan, a 65-year-old artist, is involved in a car accident. While driving, he is hit by a truck on the passenger side. He is taken to the emergency room, told he had suffered a concussion, but that it did not appear serious. But then something peculiar happens. While taking an eye exam, he discovers that he is unable to distinguish letters or colors. Letters seem to be Greek and images look like a black and white television screen. “My brown dog is dark grey. Tomato juice is black.” Eventually he is able to see letters as before, but he can never see colors again.

His condition is called cerebral achromatopsia, a type of color-blindness caused by damage to the cerebral cortex. Jonathan’s eyes are fine, but his brain is not. The accident caused irreparable damage to a part of his brain responsible for processing color, a small area of the visual cortex called V4, located in the rear of the skull.

Jonathan’s story illustrates the concept that color vision is humans’ perception of a physical phenomenon that must be interpreted by their brains. Josef Albers’ quote highlights how different this experience is among individuals. To fully understand this complexity, we first need to understand the nature of light and color.

Physics defines the word light in a slightly different manner than our everyday use of it. Physicists refer to light as the entire range of the electromagnetic spectrum. Radio waves are at the low-energy end, while x-rays and gamma rays are at the high-energy side of the spectrum. Between these two extremes there is a narrow range which is referred to as visible light. Visible because it can be detected by our eyes. This is what most of us call light.

All light, including the visible one, is made of subatomic particles called bosons, specifically some called photons. You may remember recently hearing in the news about the discovery of the Higgs boson, more commonly referred to as the “God particle”. Photons are a more common type of boson, a bit less glamorous. We can think of photons as massless small packets of discrete energy or what physicist called quanta of light. Quanta from Latin meaning amount, in this case meaning the smallest possible discrete unit of energy. Photons are the force carriers between electrically charged particles, like protons and electrons.

The difference between a radio wave and what we perceive as Red is just the wavelength or energy level of the photons. The longer the wavelength, the less energy the packet contains; the shorter the wavelength, the higher the energy. The amount or quanta of energy is determined by a simple formula consisting of the wavelength times a constant. We could say that what we perceive as Red is just a higher energy photon than a radio wave. What our eyes perceive as light are all the photons within a range of wavelength or energy levels that correspond to the visible part of the spectrum. What we perceive as different colors really are just photons at different wavelength or energy levels in that spectrum. Red light is the longest wavelength and lowest energy level, while violet corresponds to the shortest wavelength and highest energy level.

The following charts show the entire light spectrum and where visible light falls in, around the middle section, between infrared and ultraviolet. Also take a look at the factors of scale, frequency and temperature.

By Inductiveload, NASA – self-made, information by NASABased off of File:EM Spectrum3-new.jpg by NASAThe butterfly icon is from the P icon set, File:P biology.svgThe humans are from the Pioneer plaque, File:Human.svgThe buildings are the Petronas towers and the Empire State Buildings, both from File:Skyscrapercompare.svg, CC BY-SA 3.0,

The Sun is a mass generator of photons. It generates them across the entire electromagnetic spectrum from radio waves to gamma rays. It spews them out in all directions into space. Let’s  follow a single photon’s journey, it has a wavelength that most of us perceive as the color green in the range of 560–520 nm. Let’s say that our photon is traveling along with a group of other photons. This group consists of photons in a continuous range of wavelengths in the visible spectrum. This means that some would correspond to what we perceive as the color red others yellow, orange, blue and violet. Our eyes would perceive this mixture as just white light. The group leaves the surface of the Sun and about eight seconds later they start striking the suspended particles of gasses in our atmosphere, then the surface of the earth, a mountain, a rock, a tree, a leaf and so on. This is when things start getting interesting.

There is basically three things that can happen to these photons: their energy can be absorbed, reflected or transmitted. What happens depends on the atomic composition of the objects they strike. Every element in the periodic table responds differently to each wavelength or energy levels of photons. The reaction depends on the natural frequency of the electrons within the atoms. Because of this property of matter, every element in the periodic table has a distinct color signature. This property is used in spectroscopy, using light to determine atomic composition, and it is widely used in many areas of science.

In the case of the leaf, its atomic composition absorbs the energy of most of the group of photons, except for our photon.  That photon has a wavelength which corresponds to what we perceive as green. The leaf reflects that single photon which then strikes a cone cell in our retina in the back of our eye and we perceive the leaf to be green. In reality, it will take much more than a single photon for us to be able to perceive light or color, but it is a simplified example of how the process works.

If you have not noticed by now, I have been using the phrase “we perceive” several times when referring to color. This was a conscious effort because a lot of what we call color is based on perception. Our vision can be thought of as the psychological perception to a physiological response of visible light waves. That is a real mouth full, I know.  Simply, psychological perception refers to what happens in our brains, while physiological response is what happens in our eyes. Speaking about the brain’s process, or the psychological perception of light, Dr. Dennis Eckmeier, explains it best:

“Perception itself is an inner process, that has only little to do with the physical phenomenon. We don’t feel temperature as the movement of molecules, we don’t see light as electromagnetic waves but as colors.”

In other words, our response is not in line with the actual physical phenomena but an abstraction or construct of our minds.

But what about the physiological response, or more specifically, what happens in our eyes?  Eyes are the transducers or the brain’s translator of light, what eventually results in our perception of color and vision. It is estimated that most humans can see around one to two million colors. There are some people, particularly women, who may be able to see up to ten million colors. Let’s not mention other species that can see far more colors, like the zebra finch. Or even others, such as the artic reindeer, who are able to see other parts of the spectrum, like ultraviolet light. How is that possible? How is their eye structure different from ours? How do our eyes translate light, an electromagnetic wave to something that our brains abstract to color and vision? What are the limitations our eyes impose on vision and color perception? We will continue to  explore this part of the puzzle in an upcoming segment.

Written By: Pedro Suarez June 2020

We all can be explorers.

I like to think that our environment influences our childhood, and our childhood influences the rest of our lives. I grew up during the golden age of space exploration, the era where science and engineering reigned supreme. It was time of the race to space and to the Moon. It was the age of the test pilot astronaut, as well as the pocket protector and slide rulers. It felt like wearing a white shirt and a black tie and working at mission control were cool things back then. Every kid wanted to fly a jet, or better yet, a rocket and land on the Moon, Mars or some other far off planet. I remember being glued to my TV during the Apollo missions, wondering what it must feel to be out there in space, or even walking on the Moon.

The spirit of adventure and exploration were alive everywhere during those times. I still remember one of my favorite TV shows, “The Undersea World of Jacques Cousteau”. I could not wait for Sunday evening to roll around so I could finally join Jacque Cousteau and his team on the Calypso for another adventure! We would be exploring the depth of the oceans, a coral reef, or some fascinating marine environment such as the Mariana Trench about the mini sub. It was fun to imagine what it would be like to be onboard the Calypso, to wear a red diver’s cap and have access to all the cool gear. Yes, I am talking about the special dive equipment like full-face masks so they could communicate under water with the mini subs and the ROVs (remotely operated vehicle for the uninitiated). All of this made a deep impression on me. It may have been food for the mind, the catalyst that would eventually lead me to be curious about how things work, about technology and engineering.

Toys also played on the exploration and discovery themes. One of my favorites was the G.I. Joe Adventure team action figures. Some people incorrectly called them dolls, but they were action figures and don’t let anyone say otherwise. They had life-like hair and beards, and realistic human features. The adventure team was what today would be called a “politically correct” toy for its time. As a push back to the Vietnam War, Hasbro produced this set of action figures based on the original G.I. Joe in the 1960s. But instead of having a military theme, these action figures were explorers. There were several different team members: an archeologist, a pilot, an astronaut, a sea explorer, and the commander who assigned their missions. Because of my love for the oceans, I had the Sea Explorer, with dive gear and all. I fondly remember the many time I filled up the tub and played, diving under water with his sea scooter (it actually worked, batteries not included). I even built a mini sub and an underwater sea lab out of cardboard to live out more adventures, of course not inside the bath tub that would just have made a big mess. This was a time when kids made up lots of their own toys and created their own play; imagination ran wild. It was a great time to be a kid!

My childhood was filled with many adventures. The kind of stuff kids would do back in those days, think of the show Stranger Things, but without the sci-fi stuff. We would go out with our friends and explore new places on our bikes. We would find a new cool snorkeling spot that was known to no one, and which our parents most likely wouldn’t allow us to go; so, we wouldn’t tell them. We would build some cockamamie new thingamajig and go test it out; again, something else we didn’t tell our parents since we had previously taken apart some house hold appliance for some essential parts. Being very honest, most of these so-called inventions never worked, and at best would work unpredictably and sometimes even dangerously. This reminds me of the time when I rigged up my walkie talkie to plug into the wall outlet. According to my calculations, this was going to increase the range, which would allow me to talk to my friends who lived miles away. You can only imagine how that worked out…it scared the bejesus out of me and started a small fire! The fun part of this was we never knew how things would turn out; it made life an ever-unpredictable adventure.

Time passes, life happens, and at some point, you just grow up. You suddenly realize that you will not be a diver on the Calypso, or an astronaut going to space, or any type of adventure team explorer. You realize that for the most part, you will have an ordinary life. You will have an ordinary job and raise an ordinary family. This is just the way things usually work out for most people. Most of us accept this life as a simple banal existence. Then one day you realize many years have passed. The world is a totally different place from where you lived out your childhood adventures. Now there are computers in every home, maybe even in every room. Every member of the family has a cell phone, even the kids. And there is this thing called the Internet that connects everyone’s computer and cellphones to this strange place called the cloud. Nobody knows what happens in the cloud, but we all want to be connected to it.

This morning, I am on Google, a cloud-based search tool, looking for something or other most likely of no real significance. When I first open the Google page, this cool looking Google doodle pops up in the center of the screen. To be honest, I personally like the Google doodles; they are mostly funny and sometimes educational. So, I am compelled to click on it; I need to satisfy my curiosity. What is this doodle all about? Who is the person whose birthday is being celebrated today? What made them so important that we would want to remember him or her? There are so many questions rushing to my mind. Then I click.  Wow, I am floored! Its Fridtjof Wedel-Jarlsberg Nansen. Who?  Some guy I have never heard of. But wait. This guy was everything I aspired to be, a Norwegian explorer, scientist, diplomat, humanitarian and Nobel Peace Prize laureate. Well, maybe I never aspired to be Norwegian, but everything else is way cool. In his youth, he was a champion skier. He led the team that made the first crossing of the Greenland interior. I always have wanted to trek in Greenland. He won international fame after reaching a record northern latitude. His techniques of polar travel and his innovations in equipment and clothing influenced a generation of Arctic and Antarctic expeditions.

As I read the final entry from Wikipedia It suddenly hits me, I will never be anything like this guy. I will never explore Greenland or the arctic or invent cool arctic gear. I will not be living the G.I. Joe adventure team lifestyle any time soon. However, I do share one thing in common with Fridtjof, or Frit for short. It is something all explorers share, curiosity. Curiosity is the engine of exploration. To learn and to know the unknown. To venture into this new world.

Having written this, I would like to re-frame what it means to be an explore to me. Sure, I won’t be able to go into space or be part of Cousteau’s team on the Calypso. However, I feel the only requirement to have the explorer’s spirit is to remain curious. This is something we can all do and cultivate. It is also a key ingredient into being a lifelong learner. It is the Key for continued personal growth and development.

There are so many things to be curious about. I was curious about the Google doodle of the day. That led me to the discovery of some new people and facts, which in turn inspired me to write this story. Maybe I will take on the cloud next and see what makes it tick. How about learning about a new culture or language or cooking style? Perhaps explore a new hobby or develop a new skill? These are all ways that we explore. And of course, we can do some exploration of new places. Start with places you have not been in your own city or town. You’d be surprised how many there are. Even different cultures within the city. Be adventurous and even go to those parts of town that are a bit on the wild side, you know what I mean. Then travel a bit further out, perhaps to the next city, to the next county, and so on. The possibilities are endless. Perhaps I will plan a trip to Greenland and take the opportunity to practice photography there. Exploration is all around us. Just remain curious, like that little kid long ago that dreamt about going into space, playing out his fantasies along with the G.I. Joe adventure team. Cultivate your inner child, because yes, we can all be explorers.


PS: I just bought my G.I. Joe adventure team t-shirt a few weeks ago. Living the dream now!


Photo from: Vintage3Djoes

The Hidden Side of Success


Gary Monroe Lecture at FIU


“Failure is just one more iteration toward success.”

We hear this type of talk all the time, well at least I do. But the question is why is this so? Why are people so eager to embrace failure in all of its forms? Well because failure is embedded into their system of  thinking about success .

Last week I attended a lecture by photographer Gary Monroe where he discussed  his body of work on Miami Beach and Haiti during the late 70’s through the 80’s. During his talk he explained that he had shot, and actually still shoots, in black and white film. Most of the shots he takes don’t really come out right for what ever reason, he uses up a lot of film to just get in a few good shots. He gave out some percentages of what he thought was his ratio of good to bad shots something like 20% are shots he can use, the others not. Lets think about this, he fails 80% of the time, wow 80%.

Same thing happens in software development. Many times a brute force algorithms is used to solve some problems. Brute force meaning, just try as many possible combinations and see which one gets close to an acceptable answer. This is the way many early calculators would solve math problems, basically guess until you get close. As you can see failure is built into the solution, you must fail many times to succeed. Failure is hidden in the success.

However, the calculator does not show you how many guesses it took to get an approximation to the correct answer, it just shows you the correct answer, and every one is happy. The guessing is done behind the scenes at lighting speed by the processor, almost instantaneously, as far as we are concerned. Just like you don’t see 80% of the bad shots that Gary takes, we only see a fraction, the 20% , the good ones.

Because failure happens behind the scene we don’t get a real appreciation for what it takes to succeed.  We may think that its easier than it actually is, and when we are hit with our first roadblocks or first failure we think something is wrong, that we are not good enough or that our idea is not good enough. Real life is a bit messy and we don’t iterate at lightning speed, our feelings and emotions sometimes get the better of us. We all are afraid to feel the sting of failure, but we must be courageous  enough to move forward despite our fears. But the lesson is real, we must try many times, basically the brute force algorithm, at solving a problem to get it right. Think of Edison’s battery experiments, it involved over 10,000 experiments with different chemicals and materials to develop his alkaline storage battery.  When asked he said; “I found 10,000 ways that the battery did not work”.

So in short, lets keep on trying, moving forward through the adversity, the failures, we will succeed if we do not give up, as failure is the hidden side of success.


Gary Monroe, is professor of fine arts and photography. The author of numerous books, including The Highwaymen. Also featured along with Andy Sweet in the documentary “The last Resort”



Cubist Photography

David Hokney most likely known as a painter but he did photography as well. His photography tries to capture multiple perspectives kind of like a cubist painters.

I  have become very interested in this concept, as I think that truth and reality are both relative and can be experienced from infinite points of view. that being said here is the link  to interview with Hokney where he discusses his thoughts on his photos.




Capturing time

Photos allow one to share a moment in time regardless of  physical locations, to share the human experience.

To share a moment in time, how long of a moment and how does this actually occur? To do this a photo always captures the temporal dimension  in the form of shutter speed, in other words how much time is the light allowed to shine on the film or these days sensor. This time is usually in short spurts from fractions of a second for most pictures to sometimes minutes for those very long exposures.

I always been fascinated about the freezing of this temporal moment on the frame, or in other words how much time you actually captured on a single frame of film or in a digital file. But how about capturing even more time on a single frame say hours or days and compressing it to comfortably fit. This is what artist and photographer Stephen Wilkes is doing with his most recent project “Day to Night”.

See him talk about it in this recent Ted Talk.

Thoughts on Fine Art Photography

It seems that everyone has a thought on what fine art photography should be and the problem is that each one is a bit different.

My own thoughts:

Fine art photographs are an expression  of the artist vision in the photo medium, as a canvas to a painter or a piece of clay or stone to a sculptor.  This expression could be carried out anywhere in the workflow of the medium, from the actual composition and subject, to the processing technique used, as long as it is meant to express the artist vision for that particular piece.

Here are a few of my favorites fine art photographers, even though some of them may not consider themselves as such:

Cover Magazine

Red Trees on a Hill
Lost Pier

Long As I Can See The Light

My philosophy on photography

The success of an image does not solely depends on its artistic or technical merits but how many thoughts it provokes, how it makes us feel, how it stirs our emotions, how it ignites our imagination and passion, how it may change us is some way.

Photos allow one to see the world through someones  lens, it is a reflection of their mindset, their interpretation of reality. They allow one to travel to far away places and share that experience and be inspired. Photos allow one to share a moment in time regardless of  physical locations, to share the human experience.