Quote:
Originally Posted by sharptrack2
Nice project Bojan! Very professional looking. 3-D printer on my wishlist now.
I do have a curiosity question... I fundamentally understand spectroscopy and would like to know why you put a prism in front of the grating? Is that to concentrate the central target light into a smaller area, or spread it out to get better resolution?
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Kevin, this is for two reasons:
- to reduce chromatic coma
- to bring the first order spectrum closer to optical axis of the system
Those reasons are very nicely discussed on Christian Buil's webpage here:
http://www.astrosurf.com/buil/us/spe1/spectro1.htm
http://www.astrosurf.com/buil/us/spe1/spectro2.htm
However, prism is not necessary to build a good performance spectrograph with Star Analyser.