Solar limb images
VTT - Double-stacked etalons in collimated beam. Finesse of 46 for HR etalon and 36 for LR etalon.
Source : K.G Puschmann et al, The new Göttingen Fabry-Pérot spectrometer for two-dimensional observation of the Sun. A&S 451, 2006.
SST - CRISP SpectroPolarimeter - Double-stacked (high-resolution and low-resolution) etalons in telecentric beam. FHWM = 0.06 A.
Source : Pereira et al, The apparence of spicules in high resolution observations of Ca H and Ha. Astrophysical Journal, 2016.