Strange Posted April 9, 2018 Share Posted April 9, 2018 3 hours ago, Mehmet Saygın said: I do you a favor and add another link That article is about words for colour it has almost nothing to do with how colours are perceived. 1 Link to comment Share on other sites More sharing options...
koti Posted April 9, 2018 Share Posted April 9, 2018 4 hours ago, koti said: Any evidence for your claim ? I got 2 downvotes for asking for evidence on a science forum in the physics section. I wonder who the other „scientist” is. 53 minutes ago, Strange said: That article is about words for colour it has almost nothing to do with how colours are perceived. This thread shouldn't even be in the physics section as it deals with color perception which has nothing or very little to do with physics. Link to comment Share on other sites More sharing options...
Carrock Posted April 9, 2018 Share Posted April 9, 2018 3 hours ago, Mehmet Saygın said: I were also tried to explain we see the colors same, but interpret differently, (as we do everything) but you need to do more than tearing the peel from banana for understanding. If I look at an orange in daylight, or under artificial light with a different spectrum it always looks orange coloured to me because evolution has enabled me to see colours largely independent of the quality of the illuminating source. If I photograph the orange under both these conditions with no colour filtering, the orange in the photos looks to be different colours. Which if any of these colours is 'scientifically' correct? Link to comment Share on other sites More sharing options...
Bender Posted April 9, 2018 Share Posted April 9, 2018 (edited) 3 hours ago, koti said: I got 2 downvotes for asking for evidence on a science forum in the physics section. I wonder who the other „scientist” is. Don't worry, there are plenty of members here prepared to undo the damage. I was about to upvote all those downvotes, but others must have beaten me to (most of) it. The voting system works! Edited April 9, 2018 by Bender Link to comment Share on other sites More sharing options...
koti Posted April 9, 2018 Share Posted April 9, 2018 3 minutes ago, Carrock said: If I look at an orange in daylight, or under artificial light with a different spectrum it always looks orange coloured to me because evolution has enabled me to see colours largely independent of the quality of the illuminating source. If I photograph the orange under both these conditions with no colour filtering, the orange in the photos looks to be different colours. Which if any of these colours is 'scientifically' correct? This is where color management comes into play, there can be various components and technologies involved. The consumer market commonly uses sRGB or Adobe RGB in your camera into an ICC Profile on your PC/Mac OS into a CMYK ICC profile in your printer OS where all are bound by CIE LaB which is used as a color "reference language" CIE LaB is an independent color model unlike RGB or CMYK which differ between devices. Color management in professional use is almost always done by custom calibration using colorimetry calibration devices which combined with software and hardware provide calibration to all devices involved. There are custom color models used by various companies, for example Hasselblad professional still cameras have their own color workflows. Film production color management is a whole different ballgame involving customized technologies. So the answer to your question is that colours are unfortunately as scientifically correct as you make them. 4 minutes ago, Bender said: Don't worry, there are plenty of members here prepared to undo the damage. I was about to upvote all those downvotes, but others must have beaten me to (most of) it. The voting system works! Thanks Bender and others. I think I'm at what I started off with before this thread. Link to comment Share on other sites More sharing options...
Mehmet Saygın Posted April 10, 2018 Author Share Posted April 10, 2018 On 09.04.2018 at 11:34 AM, Mehmet Saygın said: human perception which is different for everyone Can someone do explain me how we perceive the colors differently,if we have the same kind of photoreceptors ? (S,M,L cones) Link to comment Share on other sites More sharing options...
koti Posted April 10, 2018 Share Posted April 10, 2018 4 minutes ago, Mehmet Saygın said: Can someone do explain me how we perceive the colors differently,if we have the same kind of photoreceptors ? (S,M,L cones) All the light data gathered by your sight aparatus is transported by your neural pathways to your brain. It is when the data is parsed by the brain when color occurs. So color will depend on a countless number of factors specific to a certain brain (previous experiences) You can do a cool experiment with your friend if you can get your hands on a color printer - Print a few pages with red (or any other color) color swatches which have values close to each other and compare them with a chosen red color. Do this seperately with your friend and compare results. I’ve done this excersize many times in my trainings and the results are always the same - everybody chooses different colors to match the target. Everybody sees colors differently. Literally. Link to comment Share on other sites More sharing options...
StringJunky Posted April 10, 2018 Share Posted April 10, 2018 11 minutes ago, Mehmet Saygın said: Can someone do explain me how we perceive the colors differently,if we have the same kind of photoreceptors ? (S,M,L cones) Different sensitivities in each cone type between individuals could render different hues. Link to comment Share on other sites More sharing options...
Mehmet Saygın Posted April 10, 2018 Author Share Posted April 10, 2018 (edited) 21 minutes ago, koti said: All the light data gathered by your sight aparatus is transported by your neural pathways to your brain. It is when the data is parsed by the brain when color occurs. So color will depend on a countless number of factors specific to a certain brain (previous experiences) You can do a cool experiment with your friend if you can get your hands on a color printer - Print a few pages with red (or any other color) color swatches which have values close to each other and compare them with a chosen red color. Do this seperately with your friend and compare results. I’ve done this excersize many times in my trainings and the results are always the same - everybody chooses different colors to match the target. Everybody sees colors differently. Literally. I am sorry for yesterday, I behave like an asshole. Is this more about to be aware of same hues but a little bit different darkness or lightness ? I mean,in fact,women are better than men categorizing the same color's variations,but we see the same color's. 20 minutes ago, StringJunky said: Different sensitivities in each cone type between individuals could render different hues. I think the differences that will cause are very small and negligible according to the working mechanism of photoreceptors. Edited April 10, 2018 by Mehmet Saygın 1 Link to comment Share on other sites More sharing options...
koti Posted April 10, 2018 Share Posted April 10, 2018 20 minutes ago, Mehmet Saygın said: I am sorry for yesterday, I behave like an asshole. No worries, forget about it. 1 Link to comment Share on other sites More sharing options...
Mehmet Saygın Posted April 10, 2018 Author Share Posted April 10, 2018 (edited) 22 minutes ago, koti said: No worries, forget about it. Thanks for this noble behaviour. On 09.04.2018 at 10:12 AM, koti said: In order to determine anything about color you need a reference point. These reference points are color models. So a certain color will have more lightness than another color only if you operate within a color model framework. If you do not use a color model it is impossible to determine anything about color besides subjective statements based onhuman perception which is different for everyone. So your statement that "yellow is the second lightest color” (what does that even mean) doesnt make sense without operating within some color model. Your question how to explain that physically is null as a result. You need to be more specific, try rephrasing what your question is. I underdstand you right now, If we look the results which based on color model analysis (i.e. CIELAB), yellow is the second lightest color next to white according to L* values. (I mean here the lightness, when I describe the yellow which is the closest color to white.) 28 minutes ago, Mehmet Saygın said: I underdstand you right now, If we look the results which based on color model analysis (i.e. CIELAB), yellow is the second lightest color next to white according to L* values. (I mean here the lightness, when I describe the yellow which is the closest color to white.) Can you explain, why is that ? Edited April 10, 2018 by Mehmet Saygın Link to comment Share on other sites More sharing options...
Bender Posted April 10, 2018 Share Posted April 10, 2018 11 hours ago, Mehmet Saygın said: I think the differences that will cause are very small and negligible according to the working mechanism of photoreceptors Wikipedia : Quote Variation in cone pigment genes is widespread in most human populations It is more than different sensitivity. The peak wavelength can vary, which is why some humans have tetrachromacy. This can only be possible if the variation is significant. (+1 for the appology and the change in attitude) Link to comment Share on other sites More sharing options...
Mehmet Saygın Posted April 11, 2018 Author Share Posted April 11, 2018 9 hours ago, Bender said: Wikipedia : It is more than different sensitivity. The peak wavelength can vary, which is why some humans have tetrachromacy. This can only be possible if the variation is significant. (+1 for the appology and the change in attitude) I also said this,but color blindness or tetrachromacy are abnormality situation. If you don't have a color blindness or tetrachromacy, we all have the same color perception. A normal trichromat human have S,M and L cones which detects short,medium and long wavelengths respectively. Link to comment Share on other sites More sharing options...
Bender Posted April 11, 2018 Share Posted April 11, 2018 There are differences in eg the M cones, which is why some people with two different M cones are tetrachromat. If all M cones were equal, there would be no tetrachromacy in humans. Link to comment Share on other sites More sharing options...
Mehmet Saygın Posted April 11, 2018 Author Share Posted April 11, 2018 6 minutes ago, Bender said: There are differences in eg the M cones Wrong example, because tetrachromats have an extra cone (for UV light detection) which is taken part in UV range of electromagnetic spectrum Link to comment Share on other sites More sharing options...
koti Posted April 11, 2018 Share Posted April 11, 2018 „Color is not a physical quantity which can be measured. Yet we attach it to the objects around us. Colors appear to be approximately constant to a human observer. They are an important cue in everyday life. Today, it is known that the corpus callosum plays an important role in color perception. Area V4 contains cells which seem to respond to the reflectance of an object irrespective of the wavelength composition of the light reflected by the object. What is not known is how the brain arrives at a color constant or approximately color constant descriptor. A number of theories about color perception have been put forward...” https://link.springer.com/chapter/10.1007/978-3-540-75555-5_9 And heres a half decent introduction to color management: http://cmc.printing.org/wp-content/uploads/2018/01/Hutcheson-FundamentalsOfColorMgt.pdf Link to comment Share on other sites More sharing options...
Mehmet Saygın Posted April 11, 2018 Author Share Posted April 11, 2018 1 hour ago, koti said: „Color is not a physical quantity which can be measured. Yet we attach it to the objects around us. Colors appear to be approximately constant to a human observer. They are an important cue in everyday life. Today, it is known that the corpus callosum plays an important role in color perception. Area V4 contains cells which seem to respond to the reflectance of an object irrespective of the wavelength composition of the light reflected by the object. What is not known is how the brain arrives at a color constant or approximately color constant descriptor. A number of theories about color perception have been put forward...” https://link.springer.com/chapter/10.1007/978-3-540-75555-5_9 And heres a half decent introduction to color management: http://cmc.printing.org/wp-content/uploads/2018/01/Hutcheson-FundamentalsOfColorMgt.pdf Despite my awful attitude,thank you for your interest in this topic According to this reference at page 11 and 12 http://cmc.printing.org/wp-content/uploads/2018/01/Hutcheson-FundamentalsOfColorMgt.pdf Yellow reflects the most amount of visible light, Is this the reason why yellow is the second lightest color and nearest color to white ? Link to comment Share on other sites More sharing options...
koti Posted April 11, 2018 Share Posted April 11, 2018 5 minutes ago, Mehmet Saygın said: Despite my awful attitude,thank you for your interest in this topic Don't worry about it. Quote According to this reference at page 11 and 12 http://cmc.printing.org/wp-content/uploads/2018/01/Hutcheson-FundamentalsOfColorMgt.pdf Yellow reflects the most amount of visible light, Is this the reason why yellow is the second lightest color and nearest color to white ? I don't see where they say anything about Yellow reflecting most of visible light on page 11 & 12. Link to comment Share on other sites More sharing options...
Mehmet Saygın Posted April 11, 2018 Author Share Posted April 11, 2018 (edited) 2 minutes ago, koti said: Don't worry about it. I don't see where they say anything about Yellow reflecting most of visible light on page 11 & 12. Reflectance vs. Wavelength graphs for inks Edited April 11, 2018 by Mehmet Saygın Link to comment Share on other sites More sharing options...
koti Posted April 11, 2018 Share Posted April 11, 2018 3 minutes ago, Mehmet Saygın said: Reflectance vs Wavelength graph Give me the slide title, I can't find it. Link to comment Share on other sites More sharing options...
Mehmet Saygın Posted April 11, 2018 Author Share Posted April 11, 2018 1 minute ago, koti said: Give me the slide title, I can't find it. These ones Link to comment Share on other sites More sharing options...
koti Posted April 11, 2018 Share Posted April 11, 2018 (edited) 26 minutes ago, Mehmet Saygın said: These ones Ok, these slides explain that in order to achieve an acceptable black color you need to add a separate ink to the CMY inks/toners. When you mix CMY in their maximum saturations you get sort of a black but its in fact brownish so printer manufacturers add a K ink/toner to get better results. Later the slides explain that there is a difference between the hypothetical ideal inks (defined by color models) and the real world results and the need to compensate for this by adding corrections. Quote Yellow reflects the most amount of visible light, Is this the reason why yellow is the second lightest color and nearest color to white ? I have no idea where you got this from,it doesn't make any sense to me. Yellow doesn’t reflect anything, its a name for a sensation which we perceive. A certain shade of yellow can be second lightest to white in some color model you chose to work with, when you select a yellow shade which is the closest to white in that particular color model. Edited April 11, 2018 by koti Link to comment Share on other sites More sharing options...
Mehmet Saygın Posted April 11, 2018 Author Share Posted April 11, 2018 2 minutes ago, koti said: Ok, these slides explain that in order to achieve an acceptable black color you need to add a separate ink to the CMY inks/toners. When you mix CMY in their maximum saturations you get sort of a black but its in fact brownish so printer manufacturers add a K ink/toner to get better results. Later the slides explain that there is a difference between the hypothetical ideal inks (defined by color models) and the real world results and the need to compensate for this by adding corrections. I have no idea where you got this, it doesn't make any sense to me. If you examine graphs carefully, you will see that graphs include Reflectance Percentage vs. Wavelength informations. Make a zoom to graphs,it will make it easier for you 1 Link to comment Share on other sites More sharing options...
koti Posted April 11, 2018 Share Posted April 11, 2018 6 minutes ago, Mehmet Saygın said: If you examine graphs carefully, you will see that graphs include Reflectance Percentage vs. Wavelength informations. Make a zoom to graphs,it will make it easier for you Which slide number? (the small pink numbering at the bottom of each slide) Link to comment Share on other sites More sharing options...
Mehmet Saygın Posted April 11, 2018 Author Share Posted April 11, 2018 9 minutes ago, koti said: Ok, these slides explain that in order to achieve an acceptable black color you need to add a separate ink to the CMY inks/toners. When you mix CMY in their maximum saturations you get sort of a black but its in fact brownish so printer manufacturers add a K ink/toner to get better results. Later the slides explain that there is a difference between the hypothetical ideal inks (defined by color models) and the real world results and the need to compensate for this by adding corrections. I have no idea where you got this from,it doesn't make any sense to me. Yellow doesn’t reflect anything, its a name for a sensation which we perceive. I found also an extra graphs which supports my idea 1 Link to comment Share on other sites More sharing options...
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