I've been researching for some time now about building a spectrohelioscope, and now I've acquired some gratings so I guess I'd better get started.
One of the most interesting designs is by Gene Frazier, described in an Amateur Scientist column in Scientific American back in 1974. What's interesting about this design is that it uses a large grating to "pick off" the intended wavelength before it even enters the telescope, and then a second grating in the synthesizer disperses this first line into an image of the sun without using Anderson prisms, moving slits, or nodding mirrors.
Question: Why do I see no later examples of this design? Has it been discredited? Is there some flaw in the physics behind it? From reading the Scientific American article, the design seems to have significant advantages over other system.
One of the most interesting designs is by Gene Frazier, described in an Amateur Scientist column in Scientific American back in 1974. What's interesting about this design is that it uses a large grating to "pick off" the intended wavelength before it even enters the telescope, and then a second grating in the synthesizer disperses this first line into an image of the sun without using Anderson prisms, moving slits, or nodding mirrors.
Question: Why do I see no later examples of this design? Has it been discredited? Is there some flaw in the physics behind it? From reading the Scientific American article, the design seems to have significant advantages over other system.