An ophthalmologic photographing apparatus includes a photographing mode selection unit configured to select one of a plurality of photographing modes respectively corresponding to different photographing conditions, an imaging unit configured to capture an image of a subject's eye, an original image data generation unit configured to process electronic data of the image captured by the imaging unit according to the selected photographing mode and to generate a plurality of original image data differing from one another in spatial resolution and gradation resolution, and an image processing unit configured to generate a electronic image for diagnosis, which has similar gradation resolution to that of each of the plurality of original image data generated by the original image data generation unit.