Abstract: A color cathode ray tube has a shadow mask. The shadow mask is provided with a layer of a material having an average Z number below 20 on the side facing the phosphor screen. The layer is preferable deposited by means of electrodeposition.

Abstract: An X-ray examination includes a filter for limiting the dynamic range of an X-ray image formed on an X-ray detector by irradiation of an object, for example a patient to be examined, by means of X-rays. The filter has a number of electrodes and grains or powder particles containing an X-ray absorbing material and suspended in a suspension liquid. When a voltage is applied to electrodes, X-ray absorbing material in the suspension will move to the excited electrodes under the influence of electrophoresis. A distribution with a desired X-ray absorption profile is adjusted by application of a suitable voltage pattern. The electrodes may have dimensions of, for example 0.5.times.0.5 mm, enabling an X-ray absorption profile to be obtained with a high spatial resolution. The X-ray absorption profile can be changed within a brief period of time, for example within one second, by changing the voltage pattern on the electrodes.