Abstract: The present invention relates to a gauge for use with x-ray machines to calibrate correct technic values (exposure, kilovoltage, processing conditions, etc.) for x-ray film to yield anatomically correct film densities over the visible density range. The gauge accomplishes this by including only four sections. In particular, a first portion for achieving correct film densities at the low end of the visible density range and a second portion for achieving correct film densities at the high end of the visible density range. The gauge also includes at least one region for achieving a slight variation in film density in each of the first and second above-named portions. The gauge may be encased by being cast in plastic of a particular thickness and absorption of x-rays. With this gauge, the radiographer examines film densities at the upper and lower limits of the visible density range to distinguish overexposure, upper limits of correct exposure, correct exposure, lower limit of correct exposure and underexposure.