The gantry of a scintillation camera is automatically counterbalanced about two parallel axes. One axis passes through the detector. The other axis is a tilt axis about which a gantry structure which supports the detector may be tilted. The gantry is also counterbalanced about an axis of rotation. A collimator may be detachably secured to the detector and automatically identified. The gantry is automatically adjusted to counterbalance it in accordance with the collimator which has been attached to the detector. In the preferred embodiment, the gantry is counterbalanced even when no collimator is secured to the detector.