An optical system for a color television camera comprises a beam-splitting arrangement for separating an incident light beam from a main objective lens into three partial beams corresponding respectively to three different parts of the visible spectrum, the three partial beams being supplied to the photoelectric cathodes of respective camera tubes. One of the partial beams is supplied to the respective photoelectric cathode by way of an intermediate lens, so that the size of the image on the photoelectric cathode is different from the size of the images on the other two photoelectric cathodes. A deflector is added to allow placement of the reduced image size camera tube perpendicular to the main objective lens.