Astronomical Fabry-Perot filter has generally two kinds of optical mountings: collimated configuration and telecentric configuration. The effects of width to radius ratio (WRR) and F-number on aberration, central wavelength and bandwidth of the filter in telecentric configuration and ring pupil situations are studied. With numerical simulation method and ray tracing, the superposition result of complex amplitude on exit surface of filter is calculated. The numerical simulation result shows that there is no obvious degradation in aberration of filter when F-number is more than 50, the offset of central wavelength increases with the decrease of WRR, the bandwidth of transmission decreases with the decrease of WRR, and the offset of central wavelength and bandwidth both decrease with the increase of F-number. When F-number is relatively small, like 100, the larger field of view and bandwidth as narrow as 5.6 pm can be obtained at the same time, which will be one of the advantages of giant ring solar telescope.