VIBGYOR: Black Letter's Place in the Glass Slab

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The discussion explores the optical behavior of black letters placed under a glass slab, particularly in relation to colored backgrounds and the VIBGYOR color spectrum. It clarifies that black is not a color but rather the absence of light, meaning black letters are only visible due to the contrast with their background. The letters will appear raised due to refraction, with their perceived height influenced by the background color. If the background is white, the black letters can create a rainbow edge effect due to the different wavelengths of light being refracted. The conversation highlights the complexities of light interaction with colors and surfaces.
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suppose one keeps a glass slab over a paper containing various colored letters, i kno the order of the height according to VIBGYOR, but what would happen if one of the letters is black?
Will it be raised the maximum or minimum?
 
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Samar117 said:
suppose one keeps a glass slab over a paper containing various colored letters, i kno the order of the height according to VIBGYOR, but what would happen if one of the letters is black?
Will it be raised the maximum or minimum?

What does 'height' mean?
What does 'raised the maximum or minimum' mean?

An ideally black object seen through a transparent coloured filter of any colour will be seen as black.

If the object is ideally black, it is because it transmits/reflects/emits no light. Putting a colour filter in front of 'no light' will change nothing.
 
what i meant was due to refraction the letters will appear raised, like the bottom of a swimming pool does and due to different wavelength of the colours, they appear to be raised at different heights... I wanted to know where the color black lies in this scale.
 
Samar117 said:
what i meant was due to refraction the letters will appear raised, like the bottom of a swimming pool does and due to different wavelength of the colours, they appear to be raised at different heights... I wanted to know where the color black lies in this scale.

Black is not a colour. Technically, you do not see the letters at all. What you do see is the edge of the letters where the non-black background starts. So the question is: What color is the background upon which the black letters sit?

If the background is red, then the letters will appear shifted as much as any other red object.
If the background is green, then the letters will appear shifted as much as any other green object.

If the background is white, then all colours of light are being reflected from it. Since they will all be refracted differently, what happens is that the black letters have a rainbow edge.

I've actually noticed this phenomenon while swimming in my pool. Around black objects, you see a rainbow fringe. (What's really cool is that it only works in one axis, the axis that is perpendicular to the angle of viewing from the surface of the water. You don't get the rainbow effect along the axis that's parallel to the water.)
 
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Thanks a lot. Precisely what I wanted to know.
 
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