> The simple spectroscopy
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.
Recently I got one very good lens the Asahi Takumar 135mm 1:2.5. This is fast telephoto lens and from my point of view a good lens should be with aperture from 1:1,2 to 1:2,8.
Moon at 45% illumination and 70x magnification. With aperture of 200mm,14,1 stops dynamic range, color depth of 23.7 bits at this image there are slight color variation on the moon surface that reveals it’s structure.
This is the beginning of my research on how dark the sky could be and what is benefit of a dark sky for astrophotography. I was inspired from those 2 sites. First one presents mathematical model of how dark the sky is.
You can find my last DSLR Astrophotography article in Bulgarian at page 76. I am sharing my last findings for this publication, Specially written for the Institute of Astronomy.
Satellites, cosmic trash or UFOs, the moving spots are everywhere on the sky. Typical satellite behavior is to reflect sun light. It should be yellow or white and could fade and shine due to its rotation.