1. A radiation image capturing system comprising: an image capturing position information holding unit for holding image capturing position information with respect to a subject of a radiation detecting apparatus, disposed in an image capturing base, the radiation detecting apparatus detecting a radiation having passed through the subject and converting the detected radiation into radiation image information; an image capturing position information acquiring unit for acquiring the image capturing position information from the image capturing position information holding unit; and a magnification adjuster for adjusting an image magnification of the radiation image information based on the acquired image capturing position information.