The invention relates to a circuit for reading charges comprising a capacitive means (C1, C2) with capacitance Ca to store charges and means of reading a voltage sampled at the terminals of the capacitive means. The capacitive means is built up from a first capacitive means (C1) and a second capacitive means (C2) with a capacitance Cb less than Ca. The read circuit comprises means of comparing the voltage read at the terminals of the capacitive means with a threshold value (Vthreshold) and means of controlling the transfer of charges stored in the first capacitive means to the second capacitive means when the voltage read at the terminals of the capacitive means exceeds the threshold value (Vthreshold). The invention is applicable to detection of radiation in the imagery field.