Abstract In all but a few of 100 patients, the divergent collimator has allowed both lungs to be encompassed in one view. Phantom studies demonstrate mild-to-moderate image distortion. There is a 50% loss of sensitivity but no loss in resolution when the divergent collimator is compared with its “1000” parallel-hole counterpart designed for the same energy range. The pinhole collimator introduces moderate-to-severe image distortion and sacrifices efficiency too much for the accompanying gain in resolution and field size enlargement. A need exists for a sister divergent collimator designed for the 80–140 keV energy range.