Left panel: CMD of all stars within the core area of NGC 1783; Middle panel: CMD of the selected field star region (rectangular area in Fig. 1); Right panel: CMD of the core area of NGC 1783 decontaminated from the field star population. However, it is not fully decontaminated as there are still some non-cluster stars left in the cleaned CMD. The two gray rectangles indicate the boxes used for fitting the SFH of the turn-off and red clump region. Note that the limits of the boxes are shifted to the non-extinction corrected data.