Colors are our response to visual stimuli via complex processes that occur in our perceptual apparatus; this includes how our eyes register colors, classify the inputs and signal them to the brain, and the way the brain decodes the signals. Much of what we know about how we see colors at this time is only theory.
How the Human Eye Works
The cornea is the transparent outer covering of our eyeballs - light enters through here. Iris muscles regulate the amount of light let in by expanding or contracting. Three kinds of refractors focus light on the back surface of the eye; the aqueous humor, crystalline lens, and the vitreous humor refractor. On the back surface of the eye is the retina, which consists of many specialized cells arranged in layers. The light goes through layers of nerve cells before reaching the rods and cones, which are the layers most important to color perception, consisting of photoreceptors named for their shapes. Rods allow us to see forms in very dim light, but only in black and white, and function in light as well as darkness; cones are what allow us to see hues. However, only about 20% of the light that even reaches the retina is registered in the photoreceptive rods and cones; the rest we do not see. At the center back of the eye is an area about 1 mm in diameter called the forea. Light falling into this area gives the sharpest color definition because the forea contains only cones. When we look for details in images, we instinctively adjust ourselves so our focal point is centered on the forea. We only see about 2 degrees of our 360 degree vision with supreme accuracy. Each eye has approximately 100 million rods and 6 million cones, which communicated with the brain via the optic nerve. Electrochemical messages are sent by photoreceptors via the optic nerve across synapses within a complex network of optic nerve fibers. Signals from rods and cones are though to be gathered and passed on via bipolar and ganglion cells. Activities from the retina seem to be integrated by the horizontal and inner associative cells. Each cone is connected to one bipolar cell and one ganglion cell in the forea. On other parts of the retina, rods and cones are bundled together instead. Information from both eyes is transmitted from them to various areas on both sides of the brain, where the information is integrated to form a single image. Almost a third of the gray matter of the cerebral cortex is involved with this process.
Seeing Colors
Scientists have no definite proof of how cones work, but they know about rods. rods contain disks of a light-sensitive pigment called visual purple, or rhodopsin. When light strikes the visual purple, it bleaches it, which reduces the electrical signals for darkness that would otherwise be transmitted by the rods. Thus in the dark, rods have very large amounts of unbleached visual purple and we can still see forms with very little light present. Rods can function at light levels up to a thousand times weaker than cones. As for cones, English physicist Thomas Young and German physicist Hermann von Helmholtz both advanced and worked on a theory called Trichromatic Theory, which goes like this : Cones contain light-sensitive pigments called iodopsins, but the functions of these pigments is still relatively unknown. What is believed is that there are three different kinds of cone pigments - one for sensing long wavelengths (the red range), medium wavelengths (the green range), and one for short wavelengths (the blue-violet range). It is thought that these primary levels mix to form color. Red and green sensitive cones predominate the retina; there are few blue-violet sensitive cones. However, this theory only explains what happens in the photoreceptors under direct light stimulation. Electrochemical signals transferred from these receptors to the brain are handled somewhat differently and the process may have more than two stages, including a stage where colors may be discerned in pairs of opposing colors. This is called Opponent Theory - a response mechanism such as specialized cells in the visual cortex registers either green or red, or blue-violet or yellow. Only one kind of signal can be carried in each color pair at a time, while the other's signal remains inhibited. Another set of cells operating respond to variations between white and black and are thought to operate in a non-opponent fashion, yielding a wide range of hues. This theory has been supported by electrical analysis of nerve cells in various animals and helps explain why we don't perceive reddish green or blueish yellow.
After Images
Opponent Theory also explains after image effects, also known as successive contrast. After image effects are visual sensations of opposite colors that occur briefly after one color stimulus is removed. A theory for this is that when signalling for one color gets fatigued, it's opponent color is no longer inhibited.
Color Constancy
Color constancy, described by E. H. Land (developer of the Polaroid camera), is the phenomenon by which colors subjectively seem to remain the same under differing kinds of illumination. E. H. Land's Polaroid camera seemed to depict all colors using only red and green, and its system could also depict all colors using only red and a yellow. In addition to this is Retinex (retina + cortex) Theory, wherein a network of tiny peg-shaped blobs in the visual cortex seem to compare visual information from an object with it's immediate surroundings so that colors in the immediate vicinity seem more important than colors seen at a distance.
Variables in Color Perception
Color sensations occur as responses of our perceptual apparatus. Colors are not necessarily inherent properties in objects. Few animals other than humans seem to see the world through trichromatic color vision like we do.
Genetic and Cultural Differences
Minimal genetic differences between two people in terms of a particular amino acid can effect their cone cells and the way they see color. Color blindedness is mostly found in men and is only diagnosed if there are major variations from the norm. Approximately 7% of men cannot distinguish between red and green.
Design Factors
A large expanse of color will appear much brighter than a very small area of the same color. If a color field is far away, it will dull and lose the sharpness of it's edges. In some cases, a smaller area of color will appear darker than a larger area. This effect depends heavily on the color of the background. All perceptions of color is effected by the colors surrounding it; adjacent colors can change each other's apparent hues. An entire art movement was dedicated to these studies of color interactions, called the Op Art Movement.
Lighting
Fluorescent lighting leaves a blue cast, although there are now expensive "full spectrum" flourescent lights that are color corrected to approximate sunlight. Incandescent lights leave a reddish-yellow cast, redder than that of the natural midday sun. Sunlight's cast continually varies in color - in the morning it should appear blue to white and then red in the later afternoon. Our perception of this phenomenon is effected by other factors, however. Visual memory is what causes us to perceive colors as unchanging. In museums, strong lights may make colors appear brighter. Walls are being opened in museums across the globe to let more natural lighting in.
Surface Qualities
In the case of pigments, color perception depends on the characteristics of the surface from which it is reflected. A 3d surface will not reflect light uniformly - reflections from it's outermost contours will be strongest, causing this contours to appear very light. A rough or porous surface will reflect light in a diffused manner and without the extreme highlights of a glossy surface. Different materials will always have different reflective qualities.
Light may be reflected in many ways. Refraction is when a ray of light is bent (refracted) and then transmitted onward the same way it was going. Transparent surfaces may reflect some light, depending on surrounding and the angle at which it is seen. They also transmit light. If the surface is shiny, the light will be reflected, but not transmitted through. Translucent and semi-opaque surfaces transmit only a little light, some is reflected, and some is absorbed. In painting, is a translucent layer of pigment and medium is spread over a white ground, some light will be reflected back upward throughout the paint, which gives brilliance and luminosity to it's colors. The more opaque the paint, the less this effect occurs. A dark ground beneath a layer of translucent paint absorbs light rays so there is no appearance of brilliance or luminosity.
Emotions
Emotional states are likely to influence color perception. Depressed people see dimmer and darker colors and when we don't like something we see, our pupils narrow, allowing in less light. However, our pupils will widen when we look at something we do like, making it appear brighter.
Nonvisual Color Perception
The ability to feel colors is not uncommon in blind people and some people perceive colors when hearing sounds. This is so common that a body of research exists surrounding this phenomenon, called synthesia. Colors associated with sounds are subjective and change from person to person. However, rising pitch and faster tempos are often associated with lighter pitches, and sombre passages tend to be associated with dark colors. Females are much more likely to experience this than men. Synthesia has been known of for 300 years, but only studied seriously by scientists within the past two decades. fMRI scans and the internet have both greatly contributed to it's study. This ability is often associated with people possessing the ability of Absolute Pitch (knowing what note any sound is without any external reference). There are both tone-color and tone-space synthesias. Tone-color synthesia (TCS) elicits a color perception where as in tone-space synthesia (TSS) musical notes are organized explicitly in a well-defined spacial array. It is believed (and has been studied to be shown very true) that Absolute Pitch modulates the effects of Tone-Color Synthesia, but not Tone-Space Synthesia. Vincent Van Gosh was thrown out of piano lessons for insisting the musical notes had colors to them, and often describe colors as having personalities (another form of Synthesia), and also mentioned that the colors he painted sometimes seemed to have musical sound for him. There is great debate over whether Synthesia requires consciousness and many books published on Synthesia have the word "blue" in the title. (http://synesthesia.info/). About one in twenty-three people have some type of Synthesia, but people differ in the intensity of their perceptions. The most common type of Synthesia is colored weekdays, perceiving colored letter and numbers is most studied by scientists, and the perception of sound and color is statistically most studied by artists. Synthesia in accordance with the neuroscientific definition occurs in about 4% of the population. Our notion of common sense is derived from Ancient Greek Aristotelian thought on the unity of experience (synthesia). Johann Wolfgang von Goethe considere synthesia-like qualities an autonomous creative force of the human imagination. Unconscious body experience is essentially synesthetic according to philosopher Maurice Merleau-Ponty, and all sensory impressions correspond to each other on a preconscious level. Most people seem to be unaware of their synesthetic potential only because they unobservant of it - many synesthetics only became truly aware of themselves as synesthetics after reading an article which put a label on their abilities. (http://web.archive.org/web/20110628222645/http://www.pucsp.br/pos/tidd/teccogs/artigos/pdf/teccogs_edicao1_2009_artigo_CAMPEN.pdf)
Wednesday, February 1, 2012
Percieving Colors Notes
Colors are not simple a function of differing wavelengths - are our response to visual stimuli via complexe processes that occur in our perceptual apparatus - involve the way our eyes register colors, classifying the inputs, transfer them to the brain, and the way the brain the decodes the signals
much of color perception can be described only theortically - don't yet know how we see colors - brain may override what the eye tells it
THE HUMAN EYE
light enters the eye through the cornea - the transparent outer covering
iris muscles expand and contract to admit more or less light through the pupil
admitted light is then focused on the back surface of the eye by 3 different kinds of refractors - the aqueous humor, crystalline lens, vitreous humor
back of the eye covered by retina - retina consists of many specialized cells arranged in layers
layer most important to color perception - photoreceptors called rods and cones
rods and conces are named because of their shapes
rods - allow us to distinquish forms in dim light, but only with black and white vision
cones - function under brighter lighting to allow us to percieve hues
we cannot perceive hues well at night
rods function in light as well as darkness
before light reaches the rods and cones through layers of nerve cells
only about 20% of the light that reaches the retina actually registers in the photoreceptive rods and cones, the rest in unseen
forea - at the center back of the eye is an area about 1mm in diameter - contains only cones - light falling on this area gives the sharpest color definition - while examining details in images, we automatically move our eyes until what we want to see is center on the forea
in only about 2 of the 360 degress field surround us do we see most accurately
each eye has approximately 100 million rods and 6 million cones - communicate with the brain via the optic nerve
photoreceptors send electrochemical messages the optic nerve across synpases (gaps) in a complex network of optic nerve fibers
bipolar and ganglion cells thought to gather and pass on signals from rods and cones
horizontal and inner associative cells seem to intergrate activities from across the retina
in the forea each cone is connected to a single bipolar cell and single ganglion cell where as signals from rods and cones on other parts of the retina are bundled together
information from the yes is transmitted to various areas on both sides of the brain, where it is somehow integrated to form a single image
almost 1/3 of the gray matter of the cerebral cortex is involved in this complex process
SEEING COLORS
scientists have no definite proof of how cones work
rods contain disks of a light-sensitive pigment called rhodopsin, or visual purple
when light strikes visual purple it bleaches, reducing the electrical signals for darkness otherwise transmitted by the rods
in the dark, rods have very large amounts of unbleached visual purple, allowing us to see forms with very little light present
rods can function at light ---? of up to 1000 x weaker than the visual system based on teh cones
cones contain light sensitive pigments called iodopsins - nature and functions still matters of conjectures
a theory is that there are 3 different kinds of cone pigments : one for sensing long (red range) wavelengths, one for middle (green range), one for short (blue-violet range). primary levels thought to mix to form all color sensations. red sensistive and green senssitve cones predominate in the retina. relatively few blue sensitive cones;
Trichromatic Theory - the icha?? of 3 different kinds of cones - first advanced in 1801 by English physicist Thomas Young. Developed mid-19th century by German physicist Hermann von Helmholtz
only explains what happens in the photoreceptors under direct light stimulation - electrochemical signals transferred from these receptors to the brain are handled somewhat differently and process may have more than 2 stages - colors may be discerned in pairs of opposing colors at this stage
Opponent theory - some response mechanism such as specialized cells in the visual cortex registers either gr or red, or blu-v or yellow. in each pair, only 1 kind of signal can be carried at a time, while the other is inhibited - pairs correspond roughly to complimentary colors on color wheel. another set of cells operating responding to variations between white and black is thought to operate in a non-opponent fashion, yielding a wide range of hues
AFTER IMAGES
opponent theory has been supported by electrical analysis of nerve cells in various animals - helps explain why we do not percieve reddish green or blueish yellow
also explains after images - visual sensations that occur briefly after a stimulus is gone
store at highly saturated color for a time and the neturally colored area, we see an illusory image of the color complimentary
may be that when signalling mechanism for 1 color is fatigued its opponent color is no longer inhibited
after image effect = successive contrast
COLOR CONSTANCY
described in 1959 - 1977 by EH Land, developer of Polaroid instant photography process - his methods and research discerned colors with much less information than was ever thought possible - both r and g and y and yellow combinations can be used to depicted colors
COLOR CONSTANCY - stange but familiar phenomenon by which colors subjectively seem to remain the same under different kinds of illumination
retinex theory - (retina plus cortex) - has been vindicated by neurobiological research that demonstrates a network of tiny peg-shaped blobs in the visual cortex at the back of the human skull - seem to compare visual information from an object with what is seen immediately surrounding it - colors in the immediate vicinity seem more important than colors seen at a distance
NEODYMIUM underglaze - pottery, purple glass
VARIABLES IN COLOR PERCEPTION
color sensations occur in the responses of our perceptual apparatus - not inherent properties of objects
few animals other than human seem to see the world through trichromatic color vision
GENETIC AND CULTURAL DIFFERENCES
minimal genetic difference between 2 people in terms fo a particular amino acid effects their cone cells and the way they see color
COLOR BLINDEDNESS - major variations from the norm. most often found in men. 7% of men cannot distinguish between red and green
EMOTIONS
emotional states liekly influence color perception
depressed people may perceive dimmer colorings
pupils open wider when looking at something we like - allows more light in
narrow when looking at something we dont like
DESIGN FACTORS
a large expanse of colo appears brighter than a vey small area of teh same color
if a color field is very far away, it will dull and lose the sharpness of its edges
in some cases, a smaller area of color appears darker than a larger area - effect depends heavily on the color
of the background
all colors are affected by the colors around them
adjacent colors cann change each others apparent hues
OP ART MOVEMENT - artists fascinated with color interactions
LIGHTING
flourescent lighting - blue cast. expensive "full spetrum" fl. are color corrected to approximate sunlight
incandescent - reddish yellow cast - redder than midday natural sunlight cast
color of sunlight continually varies - blue in the morning to white to red in the late afternoon - other factors can affect perception of this, though
we percieve colors as unchanging bc of visual memory
"The eye has evloved to see the world in unchanging colors, regardless of always unpredictable, shiftingm and uneven illumination." EH Land
Claude Monet (French impressionist 1840 - 1926) observed and painted exact same scenes under many different lighting conditions
colors may look brighter under strong museum lighting
in museums, walls are being opened up to let natural light in
in the Goodwin-stone building, Thermolux panels were installed, creating a luminosity of diffused light that extends from the 2nd to the 3rd floor galleries
SURFACE QUALITIES
color perception depends in teh case of pigments on the characteristics of the surgace from which it is felected
a 3d surface does not reflect lgiht uniformly
reflection of light from its outermost contours will be strongest making them appear very lgiht
a rough or porous matter surface will reflect lgiht in a more diffused mannner no extreme highlights of the glossy surface
materials have differing reflective qualities
REFRACTION - a ray of light passing through a transparent surface is refracted (bent) and then transmitted onward
REFLECTION AND TRANSMISSION - some light may be reflected from a transparent surface, depending on surroudnigns and the angle from which it is seen - if the surface is shiny, but not transparent, light is reflected, but not transmitted through
TRANSLUCENCE - translucent or semi-opaque surface transmits only a little light some light is reflected and some absorbed
ABSORBTION the least flection occurs when light hits a dark matter surface - the lgiht is absorbed. in opaque materials, a bright white surface reflects the most lgiht and absorbs the least
WHITE GROUND - in painting, if a translucent layer of pigment and medium is spread over a white ground, some light is reflected back upward throught the paint, giving brilliance and luminosity to its colors, the more opaque the paint, the less this effect occurs
DARK GROUND - a dark ground beneath a layer of translucent paint absorbs rather than reflects light rays so there is no appearance of brilliance or luminosity
NONVISUAL COLOR PERCEPTION
ability to feel colors through hands not uncommon in blind people
some perople percieve colors when hearing sounds - so common that a body of research exists surrounding this kind of synthesia (combining 2 forms of perceptions)
Scribin - composer who associated musical keys with color
subjective associations
tend to experience rising pitch or quickening temp with lighter colors
sombre passages - dark colors
females much more likely to experience
much of color perception can be described only theortically - don't yet know how we see colors - brain may override what the eye tells it
THE HUMAN EYE
light enters the eye through the cornea - the transparent outer covering
iris muscles expand and contract to admit more or less light through the pupil
admitted light is then focused on the back surface of the eye by 3 different kinds of refractors - the aqueous humor, crystalline lens, vitreous humor
back of the eye covered by retina - retina consists of many specialized cells arranged in layers
layer most important to color perception - photoreceptors called rods and cones
rods and conces are named because of their shapes
rods - allow us to distinquish forms in dim light, but only with black and white vision
cones - function under brighter lighting to allow us to percieve hues
we cannot perceive hues well at night
rods function in light as well as darkness
before light reaches the rods and cones through layers of nerve cells
only about 20% of the light that reaches the retina actually registers in the photoreceptive rods and cones, the rest in unseen
forea - at the center back of the eye is an area about 1mm in diameter - contains only cones - light falling on this area gives the sharpest color definition - while examining details in images, we automatically move our eyes until what we want to see is center on the forea
in only about 2 of the 360 degress field surround us do we see most accurately
each eye has approximately 100 million rods and 6 million cones - communicate with the brain via the optic nerve
photoreceptors send electrochemical messages the optic nerve across synpases (gaps) in a complex network of optic nerve fibers
bipolar and ganglion cells thought to gather and pass on signals from rods and cones
horizontal and inner associative cells seem to intergrate activities from across the retina
in the forea each cone is connected to a single bipolar cell and single ganglion cell where as signals from rods and cones on other parts of the retina are bundled together
information from the yes is transmitted to various areas on both sides of the brain, where it is somehow integrated to form a single image
almost 1/3 of the gray matter of the cerebral cortex is involved in this complex process
SEEING COLORS
scientists have no definite proof of how cones work
rods contain disks of a light-sensitive pigment called rhodopsin, or visual purple
when light strikes visual purple it bleaches, reducing the electrical signals for darkness otherwise transmitted by the rods
in the dark, rods have very large amounts of unbleached visual purple, allowing us to see forms with very little light present
rods can function at light ---? of up to 1000 x weaker than the visual system based on teh cones
cones contain light sensitive pigments called iodopsins - nature and functions still matters of conjectures
a theory is that there are 3 different kinds of cone pigments : one for sensing long (red range) wavelengths, one for middle (green range), one for short (blue-violet range). primary levels thought to mix to form all color sensations. red sensistive and green senssitve cones predominate in the retina. relatively few blue sensitive cones;
Trichromatic Theory - the icha?? of 3 different kinds of cones - first advanced in 1801 by English physicist Thomas Young. Developed mid-19th century by German physicist Hermann von Helmholtz
only explains what happens in the photoreceptors under direct light stimulation - electrochemical signals transferred from these receptors to the brain are handled somewhat differently and process may have more than 2 stages - colors may be discerned in pairs of opposing colors at this stage
Opponent theory - some response mechanism such as specialized cells in the visual cortex registers either gr or red, or blu-v or yellow. in each pair, only 1 kind of signal can be carried at a time, while the other is inhibited - pairs correspond roughly to complimentary colors on color wheel. another set of cells operating responding to variations between white and black is thought to operate in a non-opponent fashion, yielding a wide range of hues
AFTER IMAGES
opponent theory has been supported by electrical analysis of nerve cells in various animals - helps explain why we do not percieve reddish green or blueish yellow
also explains after images - visual sensations that occur briefly after a stimulus is gone
store at highly saturated color for a time and the neturally colored area, we see an illusory image of the color complimentary
may be that when signalling mechanism for 1 color is fatigued its opponent color is no longer inhibited
after image effect = successive contrast
COLOR CONSTANCY
described in 1959 - 1977 by EH Land, developer of Polaroid instant photography process - his methods and research discerned colors with much less information than was ever thought possible - both r and g and y and yellow combinations can be used to depicted colors
COLOR CONSTANCY - stange but familiar phenomenon by which colors subjectively seem to remain the same under different kinds of illumination
retinex theory - (retina plus cortex) - has been vindicated by neurobiological research that demonstrates a network of tiny peg-shaped blobs in the visual cortex at the back of the human skull - seem to compare visual information from an object with what is seen immediately surrounding it - colors in the immediate vicinity seem more important than colors seen at a distance
NEODYMIUM underglaze - pottery, purple glass
VARIABLES IN COLOR PERCEPTION
color sensations occur in the responses of our perceptual apparatus - not inherent properties of objects
few animals other than human seem to see the world through trichromatic color vision
GENETIC AND CULTURAL DIFFERENCES
minimal genetic difference between 2 people in terms fo a particular amino acid effects their cone cells and the way they see color
COLOR BLINDEDNESS - major variations from the norm. most often found in men. 7% of men cannot distinguish between red and green
EMOTIONS
emotional states liekly influence color perception
depressed people may perceive dimmer colorings
pupils open wider when looking at something we like - allows more light in
narrow when looking at something we dont like
DESIGN FACTORS
a large expanse of colo appears brighter than a vey small area of teh same color
if a color field is very far away, it will dull and lose the sharpness of its edges
in some cases, a smaller area of color appears darker than a larger area - effect depends heavily on the color
of the background
all colors are affected by the colors around them
adjacent colors cann change each others apparent hues
OP ART MOVEMENT - artists fascinated with color interactions
LIGHTING
flourescent lighting - blue cast. expensive "full spetrum" fl. are color corrected to approximate sunlight
incandescent - reddish yellow cast - redder than midday natural sunlight cast
color of sunlight continually varies - blue in the morning to white to red in the late afternoon - other factors can affect perception of this, though
we percieve colors as unchanging bc of visual memory
"The eye has evloved to see the world in unchanging colors, regardless of always unpredictable, shiftingm and uneven illumination." EH Land
Claude Monet (French impressionist 1840 - 1926) observed and painted exact same scenes under many different lighting conditions
colors may look brighter under strong museum lighting
in museums, walls are being opened up to let natural light in
in the Goodwin-stone building, Thermolux panels were installed, creating a luminosity of diffused light that extends from the 2nd to the 3rd floor galleries
SURFACE QUALITIES
color perception depends in teh case of pigments on the characteristics of the surgace from which it is felected
a 3d surface does not reflect lgiht uniformly
reflection of light from its outermost contours will be strongest making them appear very lgiht
a rough or porous matter surface will reflect lgiht in a more diffused mannner no extreme highlights of the glossy surface
materials have differing reflective qualities
REFRACTION - a ray of light passing through a transparent surface is refracted (bent) and then transmitted onward
REFLECTION AND TRANSMISSION - some light may be reflected from a transparent surface, depending on surroudnigns and the angle from which it is seen - if the surface is shiny, but not transparent, light is reflected, but not transmitted through
TRANSLUCENCE - translucent or semi-opaque surface transmits only a little light some light is reflected and some absorbed
ABSORBTION the least flection occurs when light hits a dark matter surface - the lgiht is absorbed. in opaque materials, a bright white surface reflects the most lgiht and absorbs the least
WHITE GROUND - in painting, if a translucent layer of pigment and medium is spread over a white ground, some light is reflected back upward throught the paint, giving brilliance and luminosity to its colors, the more opaque the paint, the less this effect occurs
DARK GROUND - a dark ground beneath a layer of translucent paint absorbs rather than reflects light rays so there is no appearance of brilliance or luminosity
NONVISUAL COLOR PERCEPTION
ability to feel colors through hands not uncommon in blind people
some perople percieve colors when hearing sounds - so common that a body of research exists surrounding this kind of synthesia (combining 2 forms of perceptions)
Scribin - composer who associated musical keys with color
subjective associations
tend to experience rising pitch or quickening temp with lighter colors
sombre passages - dark colors
females much more likely to experience
Wednesday, January 18, 2012
Assignment 1 : Original Pencil Design and Beginnings of Design G
Original Design:
Note: must be altered significantly for each color combination
The background lines are going to be different from design to design.
Design G: Broad Hue Range, Broad Value Range, Broad Saturation Range
Half-transparent colors with the background definitions left in.
Just the semi-transparent colors.
Color Guidelines and Info is written down in notebook.
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