The present study deals with the properties oi the Šolc type monochromatic interference-polarization filters and the possibilities of their use for solar observations. In the first part the characteristics of the Šolc filter in distinction to those of the Lyot filter are mentioned. Then, the features of some of the working Šolc type filters are studied and the results obtained by means of them are compared with the theoretically assessed values. In particular the following properties háve been investigated: the half-widths of the
individual filters and their dependence on the wavelength, the spacing of the principal maxima of the filters and their dependence on the wavelength, the spacing and intensity of the first secondary maxima, the permissible convergence of the beam of rays entering
into the filter, the dependence of the position of the maxima on the inclination of the filter to the optic axis, the dependence of the position of the maxima on temperature and the transmission of the filter. The obtained results are presented in table and diagrams.
Summarilly it can be said that the Šolc type filters offer an advantageous research tool in cases, where their considerable intensity of the secondary maxima and their high sensitivity to the convergence of the beams is not a handicap, in other words, that they are very well suited for observations of prominences in a coronograph, where their high transmission at a relatively large half-width will be appreciated. On the other hand, in cases where a smáli half-width is required, that is, first of all in observations of the
chromosphere, the use of the filters has some limitations. In the concluding part some actual cases of application of the mentioned filters for observations of prominences and of the chromosphere are demonstrated.