Uvex is a compact spectrograph, adopting the Czerny-Turner configuration, specially designed for the observation of the spectral region near ultraviolet on amateur telescopes, to shorter wavelengths than 3400 angstroms in combination with a CCD camera standard (type sensor Sony ICX-694).

The optical formula Czerny-Turner is simple. It mainly consists of two spherical concave mirrors and a diffraction grating operated in reflection. In this arrangement, the optics are perfectly achromatic since consists of exploited surfaces in reflection. In the version presented here, a cylindrical lens is added to the vicinity of the detector's plan to correct the astigmatism inherent in this combination (the 2D spectral image is otherwise very elongated along the spatial axis). This lens is the only element that the light passes through the spectrograph if Uvex is also associated with a Newton telescope, Cassegrain or Ritchey-Chrétien.

http://www.astrosurf.com/buil/UVEX/