1. A method of using an ophthalmic photographic apparatus for judging whether obtainment of information on a three-dimensional image of a given portion of an examinee's eye that is obtained by Fourier-domain OCT (Optical Coherent Tomography) is successful or not, the method comprising the steps of: processing the three-dimensional image information on the given portion that is obtained by using a Fourier-domain OCT optical system arranged to obtain a tomographic image of the examinee's eye, and obtaining an OCT front image of the given portion; and detecting a positional deviation of the OCT front image by image processing followed by evaluating whether the detected positional deviation is an allowable range or not to judge whether the obtainment of the three-dimensional image information is successful or not based on a result of the detection; detecting a positional deviation of the OCT front image from a second front image of the given portion that is obtained by using an optical system for obtaining a front image of the examinee's eye by image processing by comparing the OCT front image and the second front image, and judging whether the obtainment of the three dimensional image information is successful or not by evaluating whether the detected positional deviation is in the allowable range or not; detecting a partial positional deviation of the OCT front image from a reference image by image processing to judge whether the obtainment of the three-dimensional image information is successful or not by evaluating whether the detected positional deviation is in the allowable range or not; and outputting a result of the judging.