luis:
thanks for your answers.
here is a new equipment picture:
http://www.unigraph.de/images/Sonne2...h-35mmLunt.jpg
It`s a 225mm (200mm
free aperture caused by the lyot stop) homemade halpha coronagraph with Lunt double stack etalons. In the future this is increased to 300 mm free aperture.
cs Harald
www.unigraph.de