Abstract
It is researched a little what changes happen in sensitivity of the intensifying screen when central ray is shot obliquely to it. But as we often must have dared to shoot central ray obliquely to the intensifying screen practically, we investigated about this problem basing on a few seniors' researches. When an incident angle to the inttensifying screen is increased gradually, generally sensitivity increases at 10° to 20°, retraces its steps at 30° to 40°, more decreases, and becomes unchangable at 60° over.
