We present visible spectra of Ag-like (4d(10)4f) and Cd-like (4d(10)4f(2)) ions of Ho (atomic number Z = 67), Er (68), and Tm (69) observed with a compact electron beam ion trap. For Ag-like ions, prominent emission corresponding to the M1 transitions between the ground state fine-structure splitting 4f(5/2)-4f(7/2) is identified. For Cd-like ions, several M1 transitions in the ground state configuration are identified. The transition wavelength and the transition probability are calculated with the relativistic many-body perturbation theory and the relativistic CI + all-order approach. Comparisons between the experiments and the calculations show good agreement.