Background limited S/Ns for secondary (right column) and primary transit observations (left column). The S/Ns for the central run of a planet orbiting a G-type star for two different telescope configurations are shown. The upper row shows S/Ns for one single transit observation, the lower row when co-adding five observations. The solid bars represent the filter bandpasses of NIRCam from 2 to 5 μm and of MIRI from 5 to 20 μm. Note that the F430M filter in transmission spectra is not visible due to a low S/N below 0.001.