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Uncorrected Newtonian Coma Shape

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#1 JackJohnson

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Posted 23 June 2021 - 09:57 PM

I have been working on a ray tracing python script as a way to teach myself some vector math and learn something about optics. The

 

My program calculates how light bounces through a 200mm f/5 Newtonian tube (but currently ignores that the secondary mirror would create a shadow on the primary mirror). My program specifies that light rays start at a random point at the opening of the OTA and is given one of four discrete directions (pointing at the corners of an imaging chip, upper left, upper right, lower left, lower right).

 

I was expecting the coma to look like the "RealComa' picture (From wikipedia.

 

Instead I got the plot shown in the 'CalculatedComa' picture. Instead of one cone shape, there appears to be two. Is that the real shape, or is it indicative of an error in my program?

 

RealComa.jpg

 

CalculatedComa.png



#2 JackJohnson

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Posted 23 June 2021 - 09:58 PM

I should specify, the axis of the second plot is coordinates on the imaging chip, it is just in the wrong coordinate system



#3 EJN

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Posted 23 June 2021 - 10:36 PM

I would say your program is working correctly.

 

515X3gInyEL.jpg



#4 JackJohnson

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Posted 24 June 2021 - 05:11 AM

Thanks for confirming that, and the book recommendation!




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