My hand-made spectroscope is very compact, simple, and low cost. The spectroscope is usually smaller optical parts than the telescope, so it should be low-cost.
This picture shows the whole style of my 20cm telescope with my hand-made spectroscope. Where is the spectroscope ? That is between telescope and camera.
Take a look at inside of camera, Meade Pictor416XT. There is a lens, which is a climating lens.
There are a number of optical systems in Spectroscope. I take a orthodocs type becasue I do not want spend much money for it. This is an image of my Spectroscope optical system. Star light is focuced onto f1, and L1 colimating lens transfers it into parallel light again. The parallel light goes through a grating, and take dispersion. The dispersion light are collected by L2 lens. Finally, spectrum images are onto CCD.
Grating puroduces some order lights, so sometimes they embarass us. In this case, 0th and 1st orders appear on CCD. 0th order light means no grating images, so next image appears on CCD, and take it graph.
This spectrum is Antares in Scopius.
Exposure is 0.1 seconds.
My software scans on the line of spectrum, and finds a peak of 0th order. The first peak should be 0 nm. Wavelength scale is linear, and I can replot spectrum graph with real scale.
Resolution power depends on seeing. If good seeing, the best R.P. is 7nm at 656nm, which is about 1/100 in Spectroscope expression.
June 10th 1998
July 10th 2000