... In reality, the measured amplitude is always smaller due to atmospheric turbulence and instrumental degradation, thus the amplitude measured on a science target has to be normalized by the amplitude measured on a calibrator. Calibrators are rarely unresolved, and if bright ones are needed, they tend to be big enough to require good estimates of their angular diameter. ... A catalog of bright calibrator stars for 200-m baseline near-infrared stellar interferometry (Merand et al. ...