Robert Kohlrausch Popular Books
Robert Kohlrausch Biography & Facts
The Helmholtz–Kohlrausch effect (after Hermann von Helmholtz and V. A. Kohlrausch) is a perceptual phenomenon wherein the intense saturation of spectral hue is perceived as part of the color's luminance. This brightness increase by saturation, which grows stronger as saturation increases, might better be called chromatic luminance, since "white" or achromatic luminance is the standard of comparison. It appears in both self-luminous and surface colors, although it is most pronounced in spectral lights. Lightness Even when they have the same luminance, colored lights seem brighter to human observers than white light does. The way humans perceive the brightness of the lights is different for everyone. When the colors are more saturated, our eyes interpret it as the color's luminance and chroma. This makes us believe that the colors are actually brighter. An exception to this is when the human observer is red-green colorblind, they cannot distinguish the differences between the lightness of the colors. Certain colors do not have significant effect, however; any hue of colored lights still seem brighter than white light that has the same luminance. Two colors that do not have as great of an Helmholtz–Kohlrausch effect as the others are green and yellow. The Helmholtz–Kohlrausch effect is affected by the viewing environment. This includes the surroundings of the object and the lighting that the object is being viewed under. The Helmholtz–Kohlrausch effect works best in darker environments where there are not any other outside factors influencing the colors. For example, this is why theaters are all dark environments. An example of this lightness factor would be if there were different colors on a grey background that all are of the same lightness. Obviously the colors look different because they are different colors not just grey, but if the image were converted all to grey scale, all of the colors would match the grey background because they all have the same lightness. Brightness Brightness is affected most by what is surrounding the object. In other words, the object can look lighter or darker depending on what is around it. In addition, the brightness can also appear different depending on the color of the object. For example, an object that is more saturated will look brighter than the same object that is less saturated even when they have the same luminance. The difference between brightness and lightness is that the brightness is the intensity of the object independent of the light source. Lightness is the brightness of the object in respect to the light reflecting on it. This is important because the Helmholtz–Kohlrausch effect is a measure of the ratio between the two. Helmholtz color coordinates Similar to the Munsell color system, Helmholtz designed a color coordinate system, where chromaticity is defined by dominant wavelength and purity (chroma). The percentage of purity for each wavelength can be determined by the equation below: % P = 100 ⋅ ( S − N ) / ( D W − N ) , {\displaystyle \%P=100\cdot (S-N)/(DW-N),} where %P is the percent of purity, S is the point being assessed, N is the position of the white point, and DW the dominant wavelength. Modelling Helmholtz–Kohlrausch effect has been described in mathematical models by Fairchild and Pirrotta 1991, Nayatani 1997, and most recently High, Green, and Nussbamm 2023. Given a color's CIELAB coordinates, these methods produce an adjusted "equivalent achromatic lightness" L*EAL, i.e. the shade of grey humans think is as bright as the color. Effects on industry Entertainment It is essential for lighting technicians to be aware of the Helmholtz–Kohlrausch effect when working in theaters or in other venues where lighting is often used. In order to get the greatest effect to illuminate their stage or theater, the lighting users need to understand that color has an effect on brightness. For example, one color may appear brighter than another but really they have the same brightness. On stage, lighting users have the ability to make a white light appear much brighter by adding a color gel. This occurs even though gels can only absorb some of the light. When lighting a stage, the lighting users tend to choose reds, pinks, and blues because they are highly saturated colors and are really very dim. However, we perceive them as being brighter than the other colors because they are most affected by the Helmholtz–Kohlrausch effect. We perceive that the color white does not look any brighter to us than individual colors. LED lights are a good example of this. Aviation The Helmholtz–Kohlrausch effect influences the use of LED lights in different technological practices. Aviation is one field that relies upon the results of the Helmholtz–Kohlrausch effect. A comparison of runway LED lamps and filtered and unfiltered incandescent lights all at the same luminance shows that in order to accomplish the same brightness, the white reference incandescent lamp needs to have twice the luminance of the red LED lamp, therefore suggesting that the LED lights do appear to have a greater brightness than the traditional incandescent lights. One condition that affects this theory is the presence of fog. Automotive Another field that uses this is the automotive industry. LEDs in the dashboard and instrument lighting are designed for use in mesopic luminance. In studies, it has been found that red LEDs appear brighter than green LEDs, which means that a driver would be able to see red light more intense thus more alerting than green lights when driving at night. See also Color appearance model Bezold–Brücke shift References Yoshinobu, Nayatani (February 1998). "A colorimetric Explanation of the Helmholtz-Kohlrausch Effect". Color Research & Application. 23 (6): 374–378. doi:10.1002/(SICI)1520-6378(199812)23:6<374::AID-COL5>3.0.CO;2-W. Yoshinobu, Nayatani. (June 1997). "Simple Estimation Methods for the Helmholtz-Kohlrausch Effect". Color Research & Application. 22 (6): 385–401. doi:10.1002/(SICI)1520-6378(199712)22:6<385::AID-COL6>3.0.CO;2-R. Further reading High, Gregory; Green, Phil; Nussbaum, Peter (December 2022), "The Helmholtz-Kohlrausch effect on display-based lightcolors and simulated substrate colors", Color Research and Application 2023, 48(2): 167‐177, doi:10.1002/col.22839 Sanchez, J. Michael; Fairchild, Mark D. (June 2002), Chung, Robert; Rodrigues, Allan (eds.), "Quantification of the Helmholtz-Kohlrausch effect for CRT color monitors", Proceedings of the SPIE, 9th Congress of the International Colour Association, 4421: 607–610, doi:10.1117/12.464613, S2CID 173181815 External links The geometry of color perception LED Projection Enters the Mainstream. Discover the Robert Kohlrausch popular books. Find the top 100 most popular Robert Kohlrausch books.
Best Seller Robert Kohlrausch Books of 2024
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Saltwater Cove
Amelia AddlerSecond chances...and the secrets that sabotage them. At 48 years old, Margie Clifton never expected to be starting her life all over again. But when her brother gifts her a propert...
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Pride and Prejudice
Jane AustenAn Apple Books Classic edition. Jane Austen’s beloved classic opens with this witty and very memorable line: “It is a truth universally acknowledged, that a single man in possessio...
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The Honeymoon Homicide
J. R. Mathis & Susan MathisEnjoy this SmallTown Murder Mystery Featuring A Unique Sleuthing Couple I'm Father Tom Greer, a Catholic Priest in a smalltown parish who never expected this . . . When I came...
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Get Lucky
Lila MonroeFall for the hot and hilarious romcom spin on 'The Hangover', perfect for fans of Tessa Bailey, Ali Hazelwood, and Emily Henry! What happens when you wake up in a hotel s...
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Teased by Fire
Molly O'HareFrom USA Today bestselling author Molly O’Hare comes an enemiestolovers, older brother’s best friend, romantic comedy with a curvy, antisocial, supernaturalobsessed, allyearround h...
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Dream Psychology
Sigmund FreudAn Apple Books Classic edition. Written by the founding father of psychoanalysis, Sigmund Freud’s 1899 book is the definitive text on learning to interpret dreams. Freud’s groundbr...
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Peace on Earth
Maia RossCrime never takes a holiday. Why should Irma? Irma Abercrombie is an energetic retiree with a shadowy past, a mean right hook, and a profound love of Christmas. Surrounded by seaso...
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A Bookshop to Die For
M.P. BlackDitching her fiancé at the altar, Alice Hartford bolts to her childhood hometown to reconnect with the last, happy remnant of her past: her mom's old bookstore. But the bookst...
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The Four Loves
C. S. LewisThe Four Loves summarizes four kinds of human loveaffection, friendship, erotic love, and the love of God. Masterful without being magisterial, this book's wise, gentle, candi...
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Hard Love
Peyton BanksHe was football royalty. Legendary quarterback. A champion.  Reiner Strickland had led his team to three national championships and playing a knight in shining armor was a...
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School of Potential
W.J. MayUSA Today Bestselling author, W.J. May brings you a continuation of the international bestselling series, The Chronicles of Kerrigan! Come back and enjoy the famous characters, or ...
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Nothing to Hide
Scarlett FinnPrize of a lifetime: travel the world with a celebrity billionaire. Come to LA with us, Roxie… It will be so much fun! We have tickets for a latenight talk show! What could possibl...
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Hot Off the Press
Lexy Timms"This is what really happened… reported by a free press, for a free people…" Wes Shaw leads a secret double life. As the secret owner of a billion dollar newspap...
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Silenced Girls
Roger Stelljes“ Wow wow wow!  Grips you in a choke hold and  does not let go … Oozes suspense and  bonechilling twists and turns .  Astonishing … One of those...
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Salvation
Meghan O'FlynnIf you like mouthy detectives, serial killers, and suspenseful mysteries that don't quit, this chilling and actionpacked hardboiled detective series has you covered! Try this ...
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Dracula
Bram StokerAn Apple Books Classic edition. Few characters have seized readers’ imaginations quite like Count Dracula of Transylvania, the hero of Bram Stoker’s classic. The 1897 novel put vam...
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Caught Up with the Captain
Kait NolanCan a retired naval commander and the love he left behind overcome a 34yearold secret to find their way to a second chance? Captain Mitchell Greyson is a man who believes in duty. ...
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Whiskey Girl
Melissa BelleThey'll do anything for each other…except commit. Logan Wild isn’t just the hottest broncriding cowboy in Texas. He’s also my best friendwith benefits. And that’s all we’ll ev...
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The Icing on the Cake
Linda SeedShe’s a baker without a kitchen. He’s got a double oven to spare. It’s a recipe for success, until his mother starts stirring up trouble … Cassie Jordan has a sweet dream to open a...
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Pretty Little Lies
Ivy ThornFour years ago, Nicolo Marchetti took my innocence. But he left me with something else Nicolo almost took everything from me. My virginity, my reputation, and very nearly my future...
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The Count of Monte Cristo
Alexandre DumasAn Apple Books Classic edition. Alexandre Dumas’ classic paints a portrait of Edmond Dantès, a dark and calculating man who is willing to wait years to exact his perfect plan for r...
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Little Women
Louisa May AlcottAn Apple Books Classic edition. Meet the Marches! Louisa May Alcott’s classic introduces us to four unforgettable sisters: beautiful Meg, tomboyish Jo, delicate Beth, and Amy, the ...
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Masters of Restraint
Ines JohnsonMy new boss is good at giving orders. But his latest demand is NSFW. Especially when his two business partners want in on our deal. My new boss My boss’s boss Their investor &#...
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The Scarlet Letter
Nathaniel HawthorneAn Apple Books Classic edition. Hester Prynne lives in infamy. After committing adultery and bearing a child with a man whose name she refuses to divulge, the heroine of Nathaniel ...
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How to Choose a Guy in 10 Days
Lila MonroeThe only thing more hilarious than the movies is… real life?! Fall in love with the sizzling grumpysunshine romantic comedy perfect for fans of Sophie Kinsella and Ali Hazlewood! ...
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Tempting the King
Jessa YorkAn escaped Mafia Queen, hiding from her past. A Mafia King who wants to claim her… Giselle They think I'm lostbut I know better. I can never be found. The path I've creat...
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Silver Santa
Lacey SilksTrapped together on Christmas, their unintended onenight stand becomes a lifechanging encounter amidst the snow. Laura Young's professional role as a security guard at the Sil...
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The Great Gatsby
F. Scott FitzgeraldAn Apple Books Classics edition. The Roaring Twenties are in full effect in F. Scott Fitzgerald’s riveting classic. Manabouttown Jay Gatsby seems to have it all, including loads of...
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My Paper Heart
Magan VernonOne piece of paper can change everything After my parents received the letter I failed out of college, they didn't ask questions. They just sent me to work for my great aunt i...
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Never Enough
Lexy TimmsBe good enough never is... Anthony Accardi is a man on a mission: make his father's watch company a success while bringing in millions of dollars. To do that, he needs an assi...
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Coffee Girl
Sophie SinclairMackenzie "Kiki" Forbes finds herself in a pickle. Either become her snarky sister's nanny, or move halfway across the country to work as assistanttothestylist of a ...
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Holy Bible
The Church of Jesus Christ of Latter-day SaintsThe 2013 edition of the Holy Bible contains all of the study aids contained in the 1979 edition and includes revisions to the study aids, several new photos, updated maps, and adju...
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His Own Heaven
Jennie KewWinner of the 2021 Passionate Plume Award for BDSM Romance Finalist in the 2021 Stiletto Contest for Contemporary Romance He taught her to trust, she taught him to love. Lucy Bar...
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Just Me
Lexy TimmsWe all need somewhere where we feel safe… After leaving her abusive husband, Katherine Marshall is out on her own for the first time. She's hopped from city to city to avoid t...
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All Fired Up
Kathryn ShayCaptain Jarek Zenko, a war veteran and firefighter, meets Lacey Roth at a bar one night. They don’t share their real identities, even when they retreat to a hotel. When they meet t...
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Think and Grow Rich
Greg Habstritt & Napoleon HillThink and Grow Rich is one of the most popular success book of alltime, having sold more than 60 million copies since it was first published more than 70...
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Wuthering Heights
Emily BrontëAn Apple Books Classic edition. If you’ve only ever seen Wuthering Heights on screen, you may have an image of Catherine and Heathcliff as the ultimate starcrossed lovers. But that...
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The Holy Bible - King James Version
King JamesHoly Bible King James Version Few Sample Paragraphs from The Holy Bible eBook, Genesis (OT) 1 Gen. 1 IN the beginning God created the heaven and the earth. 2 And the earth was with...
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Eternal
W.J. MayShe will fight for what is hers. When the king is murdered, Katerina, his only daughter, must flee for her life. She finds herself on a strange and dangerous path. Alone for the fi...
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You Are Kind
Michael GordonA little kindness goes a long way. How can you help encourage your kids to be kind from a young age? Teach kindness to preschoolers Acts of kindness can be fun, easy, and make a ...
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The Adventures of Sherlock Holmes
Arthur Conan DoyleAn Apple Books Classic You get not one, not two, but 25 gripping mysteries in Arthur Conan Doyle’s first of five collections of Sherlock Holmes short stories. Follow the brilliant ...
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Escape, A New Life
David J AntocciTo save herself, she had to lose everything. Trapped in a tropical paradise with no memory of how she got there, Abby is thrust into a fight for her life. Hunted by a madman, and c...
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Bewitching a Highlander
Roma CordonDefying all for the love of a bewitching lass. Breena MacRae, a healer from Skye with a touch of witchery in her blood, embarks on a dangerous search for her missing father. She ar...
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Man In The Water
Jon HillAn attempted murder. A missing spouse. And an international conspiracy that could change the world. Jack Green has always been skeptical of socalled facts. Though he's forced ...
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The Seduction Series Boxset
Roxy Sloane“Sensual, thrilling and wild!”   Discover the bestselling series in one collection: THE SEDUCTION, THE BARGAIN, and THE INVITATION. Perfect for fans of Ana Huang, Sierra S...
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Always Yours
Claire RayeSome things are just meant to be... Ellen Somerville and Will McIntyre met by accident and under unusual circumstances. Getting sprayed by a skunk in a parking lot wouldn’t normall...
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Rogue Alpha
Kimber WhiteOne touch made her crave him. But the pull of fate could be the path to ruin. College student Laura Prince lands a plum internship deep in the Michigan wilderness. When she discove...
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Assisting the Bosshole
Kristin MacQueenNo hot water? Check Missed the train? Check Broke my heel? Check Dropped my coffee? Check My first day of my new job can’t possibly go worse, right? Wrong. When I meet Parker Scott...
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Becoming Lady Dalton
Carrie LomaxA dance of desire and deceit... In the glittering world of London's ton, Mrs. Viola Cartwright revels in her newfound freedom as a lady of leisureuntil a series of jewel theft...
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Death at Hazel House
Betty Rowlands‘Riveting, can't put it down! I love this story… a wonderfully twisted tale of a crime that has more twists than I thought possible... fantastic.’ Goodreads Reviewer, 5 stars ...