Subtractive color

[koti]

Could be, I looked up on Kodachrome and it says it uses a Subtractive color method in storing the images that requires the use of glass plate negatives. I think Kodak films are stored with subtractive colors, but I could be wrong

 

All film negatives are subtractive color based (explanation below)

Kodachrome is over 100 year old analog film technology. And a very specific one too, requiring K-14 chemical process to develop the film and uses only 2 primary colors for storing color information. "Kodachrome" was actually one of the first if not the first analog film technology that used a subtractive color model for storing colors (previously they tried to use additive models and the results were awful). It is true that a film negative (any film negative) uses inverted colors that correspond to a subtractive color model - Reds appear as Cyan, Greens as Magenta and Blues as Yellow. That's because the film does not emit light so it doesn't make sense to use an additive color model like RGB - the result would be bad color rendition. When you shine bright, white light from a projector through a negative (old family slides in your basement for example) it will result in proper RGB color rendition on your living room wall - proper for a human eye that is. Let's leave the analog systems for now and please consider this as to your original question (once again) :

 

1. A source of light forces use of an addtitive color model like sRGB* (monitors, projectors, tablets mobile phones, LED panels - anything with a source of light)

2. Lack of source of light forces use of a subtractive color model - like CMYK (colors that you see on paper, cloth, wall paint, car paint, etc)

3. To make sRGB* and CMYK to be able to talk to each other you need a color magagement system. If your'e on windows and you hit print, the RGB image on your monitor is being ripped by your printer driver and the electronics inside your printer into a CMYK image which is understandable for your printer.

*CIELAB is a reference color model used by software and hardware to talk to each other color wise.

 

 

*sRGB - a global standard RGB color model developed by companies to make it easier for hardware to talk to each other. Different technologies give different results (for ex. CRT, TFT, LCD) Adobe has it's own standard called "Adobe RGB" - there are also others for specific uses.

 

*CIELAB is a color model which is independent from hardware and software and is referred to as what "humans can see" (which is not true btw because we can see more) CIELAB is used as a refererence color model for making RGB, CMYK, SWOP and anything else to be able to talk to each other in the digital world.

 

CMYK - There is no global standard here, everybody uses their own technology to print colors as well as possible - CIELAB is the reference.

 

P.S. So Koti, the subtractive color should exist, probably not with the CYMK method, thing is a Kodak film looks rather transparent. Kind of wondering what's with all the mysteries surrounding these things

 

Subtractive color exists on paper which doesn't emit light.

Additive color exists on your monitor which emits light.

No mystery

Read the 3 wiki's I linked you.

 

If you want invisible stuff look up polarization

 

Edited October 31, 2016 by koti

[fredreload]

Hmm, I found some film negative image on Google, but it doesn't look that appealing, and it is probably not true subtractive color as you've mentioned. You are right, once the light passes through the negative glass filter it becomes the color of the negative glass, hence negative color. Why do I keep thinking that film and subtractive color has to do with black hole. Is there a rumor on this, if it is misleading then I would just forget

[koti]

Hmm, I found some film negative image on Google, but it doesn't look that appealing, and it is probably not true subtractive color as you've mentioned. You are right, once the light passes through the negative glass filter it becomes the color of the negative glass, hence negative color.

You are finally on the right track. Good to see that my mumbling didn't go into nothing.

 

Why do I keep thinking that film and subtractive color has to do with black hole. Is there a rumor on this, if it is misleading then I would just forget

Black hole is a concept of an area of spacetime with infinite density in an infinitely small volume and infinite spacetime curvature.

I'd suggest you rather forget as soon as possible this weird and preposterous connotation of subtractive color model and black holes.

[fredreload]

 

Hmm, I found some film negative image on Google, but it doesn't look that appealing, and it is probably not true subtractive color as you've mentioned. You are right, once the light passes through the negative glass filter it becomes the color of the negative glass, hence negative color.

You are finally on the right track. Good to see that my mumbling didn't go into nothing.

 

Why do I keep thinking that film and subtractive color has to do with black hole. Is there a rumor on this, if it is misleading then I would just forget

Black hole is a concept of an area of spacetime with infinite density in an infinitely small volume and infinite spacetime curvature.

I'd suggest you rather forget as soon as possible this weird and preposterous connotation of subtractive color model and black holes.

 

That would be a good idea

[tar]

fredreload,

 

An interesting experiment to do with yourself, to understand light (RGB) and perception, as well as pigments (CMYK) and the absorbtion of light is to place a dot on a colored picture and stare at the dot for the count of 35 mississippis. Have a white sheet of paper prepared with a dot on it. After the count stare at the dot on the white sheet for about 5 seconds and you will see the image you were looking at at first appear in complementary colors.

 

This is because the cones in your eyes responsible for picking up RGB wavelengths are somewhat fatigued after 35 seconds and the ones that where activated the most, have used up their chemicals which are quickly restored, but in the meantime, when you look at a white piece of paper, which has all the wavelengths reflected to your eye, the cones responsible for each position of the image will not be able to pump out the chemical for the color seen during the 35 seconds and you will instead experience the exact image, in terms of position and shape, in complementary colors. Magenta for Green, Yellow for Blue, and Cyan for Red.

 

It is complicated to think through what you will see with various wavelengths of light emitted or reflected from a surface and going through various filters and bouncing off various surfaces that absorb certain frequencies and reflect others, and then enter your eye and activate various of the red and green and blue cones in your eye, but doing this experiment and thinking about light in terms of what frequencies are emitted, absorbed and reflected, will help you better understand and predict what the results will be when various filters are applied to various light sources.

 

Regards, TAR

by the way, subtractive color has to do with pigments, and pigments absorb certain frequencies, leaving the rest to reflect and reach your eye...hence those frequencies that have been absorbed, have been "subtracted" from the spectrum of wavelengths originally shone upon the object

or of course a filter could "subtract" certain frequencies

Or, consider what is happening when you see a green leaf or blade of grass. The sunlight which has light frequencies in the infrared-visible-ultraviolet spectrum includes the visible spectrum of rainbow colors Red, Orange, Yellow, Green, Blue, Indigo and Violet. The chlorophyll absorbs (subtracts, absorbs and utilizes the energy in the red, orange, yellow, and the blue, indigo, violet areas of the spectrum and reflects the stuff in the middle, making the thing appear green.

Edited November 5, 2016 by tar

[fredreload]

fredreload,

 

An interesting experiment to do with yourself, to understand light (RGB) and perception, as well as pigments (CMYK) and the absorbtion of light is to place a dot on a colored picture and stare at the dot for the count of 35 mississippis. Have a white sheet of paper prepared with a dot on it. After the count stare at the dot on the white sheet for about 5 seconds and you will see the image you were looking at at first appear in complementary colors.

 

This is because the cones in your eyes responsible for picking up RGB wavelengths are somewhat fatigued after 35 seconds and the ones that where activated the most, have used up their chemicals which are quickly restored, but in the meantime, when you look at a white piece of paper, which has all the wavelengths reflected to your eye, the cones responsible for each position of the image will not be able to pump out the chemical for the color seen during the 35 seconds and you will instead experience the exact image, in terms of position and shape, in complementary colors. Magenta for Green, Yellow for Blue, and Cyan for Red.

 

It is complicated to think through what you will see with various wavelengths of light emitted or reflected from a surface and going through various filters and bouncing off various surfaces that absorb certain frequencies and reflect others, and then enter your eye and activate various of the red and green and blue cones in your eye, but doing this experiment and thinking about light in terms of what frequencies are emitted, absorbed and reflected, will help you better understand and predict what the results will be when various filters are applied to various light sources.

 

Regards, TAR

by the way, subtractive color has to do with pigments, and pigments absorb certain frequencies, leaving the rest to reflect and reach your eye...hence those frequencies that have been absorbed, have been "subtracted" from the spectrum of wavelengths originally shone upon the object

or of course a filter could "subtract" certain frequencies

Or, consider what is happening when you see a green leaf or blade of grass. The sunlight which has light frequencies in the infrared-visible-ultraviolet spectrum includes the visible spectrum of rainbow colors Red, Orange, Yellow, Green, Blue, Indigo and Violet. The chlorophyll absorbs (subtracts, absorbs and utilizes the energy in the red, orange, yellow, and the blue, indigo, violet areas of the spectrum and reflects the stuff in the middle, making the thing appear green.

Thanks for the detailed explanation!