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CHROMATISM (2)

To represent the colours seen through a telesope is not as easy as it sounds. Below is an image of the colour-spectrum as most people see it. The colours in this image are depicted assuming comparable intensities. But we can actually see more and deeper purple as long as the light-source is bright enough.

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This shows a simulation of the above spectrum for a 0.5 wave lower spherical diffraction pattern. The numbers below the images show the used wavelengths in nm. No spherochromatism was taken into account, therefore these images are only possible for reflectors. Refractors should show more colours.

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The final image looks like this. On the left the chromatic image and on the right a non-chromatic version of the same aberation. Clearly most of the colours are situated on the edges of the diffraction ring.

Below: Two times a collection of four images. In the compositions the above left image stands for 0.5 wave of coma, above right 0.5 wave of Lower Spherical, below left 1 wave astigmatism, below right 0.7 wave pinched. The composed image on the left is nice to study the colour-effects but the image on the right is closer to what you would see at the eyepiece. The left image uses very high (unrealistic) levels of magnification that would normally also lead to a lot of light loss and far dimmer (probably nearly black) images. So the right image stands for a view through a reflector with the above aberrations. The next step will be a simulation for a refractor where the focus for different wavelengths is not the same and will introduce other effects. The next step is real telescopes in the simulation

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