F-19 NMR spectra of 11-cis and 9-cis isomers of six fluorinated rhodopsin analogs with the label(s) located at the vinylic positions of the polyene chain (8-F, 10-F, 12-F, 14-F, 8,12-F-2, 10,14-F-2) are reported along with their UV-vis and CD spectra. The regiospecific F chemical shift data are analyzed in terms of chromophore changes and local perturbation resulting from specific interactions with protein. Two analogs (11-cis-12-F and 11-cis-8-F) and also 9,11-di-cis-12-F possess FOS (fluorine opsin shift) values uniquely different from others. Ab initio F NMR chemical shielding calculations of model structures provide support that a strong protein perturbation to the 12-F position prevails in the binding cavity and that F-8 shift is sensitive to variation of the nearby dihedral angle(s). Possible causes for the broad line width of the F signals of these membrane proteins are discussed.