At present the best energy resolution for gamma-quanta and electrons in high energy physics experiment is obtained with electromagnetic calorimeters based on scintillation crystals. In 4pi detectors, to combine the high energy resolution for photons with momentum analysis for charged particles, the electromagnetic calorimeter is placed inside a magnetic field. This excludes application of conventional PM tubes. The usual solution for the current large detectors is usage of Tl doped CsI crystals with the light read out by silicon PIN diodes. At low energies the energy resolution of such calorimeter is dominated by the electronic nose, the achieved level which is 150-200 keV of equivalent energy deposition. Another solution was proposed for an endcap calorimeter of the KEDR detector where CsI crystals doped with Na viewed by vacuum phototriodes are used.