Optical depth (τ) in the wavelength range of CHEOPS, TESS, and Spitzer space telescopes at every pressure level for the simulation labeled 4P-T (left) and 4 P–T with TiO (right). In the left panel of each figure is depicted the optical depth at each atmospheric pressure level. In the right panels there are the cumulative contribution functions at each atmospheric level for the CHEOPS, TESS and Spitzer space missions. In the presence of optical absorbers, CHEOPS and TESS can probe at a higher level than Spitzer compared to a case without optical absorbers.