A complete set of experimental vibrational band transition probabilities, including recent measurements on v'=2 and 3, allows us to calculate an empirical electronic transition moment, R-e(r), for the A (2)Sigma(+) -X (2)Pi(i) system of OH, over the range of internuclear distance 0.70-1.70 Angstrom. A comparison with an ab initio moment confirms that theoretical shape and validates its quantitative results, as the calculated R-e(r) is within experimental uncertainty of the present result. The experimentally derived R-e(r) is used along with Rydberg-Klein-Rees (RKR) wave functions to calculate transition probabilities for a wide range of vibrational and rotational levels. The study is extended to the isotope OD.