Abstract: An angle indicating device is provided for measuring the angle of an X-ray machine and to display the angle on the photographic plate at the time it is exposed to X-rays. The invention includes the combination of a pendulum mounted to maintain a vertical orientation during rotation of the X-ray machine about its horizontal axis, and an indicator for indicating the angle of the X-ray machine relative to a vertical orientation of the pendulum. Furthermore, a scale and a scale indicator, both of which are opaque to X-rays is provided to project the read out of the angle indicator upon the photographic plate.