[Mitko Gorgiev (OP)]

These posts have been removed as they contravene both the rules on material published elsewhere and advertising.

[Bored chemist]

See also:
Why is the sky blue? How does light make colors appear?
https://www.thenakedscientists.com/forum/index.php?topic=78830.0

In particular see the  part that says "MODERATOR WARNING:
THIS POST AND OTHERS BY THE SAME POSTER APPEAR TO BE EDUCATIONAL IN NATURE, HOWEVER THEY CONTAIN SERIOUS ERRORS AND SHOULD NOT BE TAKEN AS SCIENTIFIC PRINCIPLES."

[Mitko Gorgiev (OP)]

In particular see the  part that says "MODERATOR WARNING:
THIS POST AND OTHERS BY THE SAME POSTER APPEAR TO BE EDUCATIONAL IN NATURE, HOWEVER THEY CONTAIN SERIOUS ERRORS AND SHOULD NOT BE TAKEN AS SCIENTIFIC PRINCIPLES."

Well, the Naked Science God got tired of fighting untruthfully against the truth.

P.S. Haven't you found any Wikipedia article to contradict my claims?

[Bored chemist]

P.S. Haven't you found any Wikipedia article to contradict my claims?

based on your previous stuff, I didn't even bother to read your post carefully.

If you think there's something wrong with physics
(1)
check that you actually understand the physics and
(2)
let us know what the problem is.

[Mitko Gorgiev (OP)]

If you think there's something wrong with physics
(1)
check that you actually understand the physics and
(2)
let us know what the problem is.

These posts have been removed as they contravene both the rules on material published elsewhere and advertising.

[Bored chemist]

Do you really not understand that " a bad diagram in a text book" is not " a problem with physics"?

Here's a better teaching site
https://spark.iop.org/spectrum-colours-dispersion-light#gref
And their picture looks like the sketch you drew.
But the real thing you have missed is this

The two diagrams are both pretty nearly correct, but they show different things.
Did you notice that
You seem to have nearly grasped it where you say

at the beginning there is no green color at all.

How far do you need to go before it's o longer "at the beginning"?
Well it's far enough that the separation of the different colours is bigger than the width of the beam,

In Goethe's picture the beam is wide
In the other picture the beam is narrow.

Did you not see that?
Did yo not understand why that is why the spectra look different?

Or did you really think that

This drawing for example is the greatest fraud in the history of science:

?

[JohnnyE]

One of the most common optical structures is the achromatic doublet. It is used to reduce chromatic aberrations.  At its most basic, it is a two lens system configuration where one lens is a concave lens, usually made of a flint glass, and the other is a convex element, usually made with crown glass.

Why these shapes and materials?

First, we need to understand what is chromatic aberration and why it occurs.  Chromatic aberration is the effect caused by the change in refractive index for a given material at different wavelengths.  For example, BK7 has a refractive index of 1.5228 at 480 nm (blue) and of 1.5131 at 700 nm (red).  That basically means that if we have a biconvex lens made with BK7, it will focus red and blue light at different points, resulting in chromatic aberration.

In order to reduce chromatic aberration, we need to find a way to match the lens focal length regardless of the wavelengths we are using. A way to do this is by using an achromatic doublet.  As mentioned before, the achromatic doublet has two lenses:  a negative lens (concave) and a positive one (convex).  The basic idea is that both lenses will compensate their respective dispersions and cancel each other.


John and Viktor

[Bored chemist]

One of the most common optical structures is the achromatic doublet. It is used to reduce chromatic aberrations.  At its most basic, it is a two lens system configuration where one lens is a concave lens, usually made of a flint glass, and the other is a convex element, usually made with crown glass.

Why these shapes and materials?

First, we need to understand what is chromatic aberration and why it occurs.  Chromatic aberration is the effect caused by the change in refractive index for a given material at different wavelengths.  For example, BK7 has a refractive index of 1.5228 at 480 nm (blue) and of 1.5131 at 700 nm (red).  That basically means that if we have a biconvex lens made with BK7, it will focus red and blue light at different points, resulting in chromatic aberration.

In order to reduce chromatic aberration, we need to find a way to match the lens focal length regardless of the wavelengths we are using. A way to do this is by using an achromatic doublet.  As mentioned before, the achromatic doublet has two lenses:  a negative lens (concave) and a positive one (convex).  The basic idea is that both lenses will compensate their respective dispersions and cancel each other.


John and Viktor

Are you the author of this work?
https://www.opticsforhire.com/blog/achromatic-doublet-with-flint-crown-glass

[JohnnyE]

Yes, we authored the article in question.  We excerpted from the text.

John