> The simple spectroscopy

  • Posted on: 25 April 2019
  • By: tihomiry

I recently bought a pocket spectroscope for laboratory use. You can find it at Ali for 5$. It is with glass prism and well build. So I did some test to use with a telescope but did not
bring any good result, so I cut it and strip the optics. Left only the prism and place it inside a eyepiece projection tube. Also place a 17 mm plossl in front of the prism. Result is
a home made spectroscope that I can use for bright star spectrum and light pollution analyses. This task well fitted to my new Vixen VMC110 as the flap mirror help a lot of
locating the targets. Below are my first tests

This is a image of Betelgeuse. The white color is IR spectrum as expected from a Red giant:

This is Sirius system. You can see that most of it is a blue light as expected from a Blue hot giant:

This is led street light spectrum. It is not good that it emits in all the visible spectrum:

This is sky pollution background. Simmilar to the street light spectrum.

If you have used DeepSky stacker to stack RAW files, maybe you have notice that the resulting image is poor of color saturation. This is because it has a higher number of bits then the display could show.

Last test from passed night put an end of the questions witch is better CCD or CMOS. My old CCD K-m fall back compared to CMOS K-5.

HDR stands from High Dynamic Range. In short it is the number of tones that compose the image. The larger it is, the best capability we have to see details in the bright and dark regions of a scene.

Witch is better. Stack or long exposure? It depends…

NGC 7000, South America nebula in Cygnus, taken by me from NAO Rozhen. 2 shots composed by 45 frames @ 30s, ISO 51200 with SW 200pds and Pentax k-5. Same processing with DeepSky Stacker and LightRoom.