Top: colour-scale image of A1682 on a log stretch from −90 μJy beam⁻¹ to 0.29 Jy beam⁻¹ (the brightest pixel is 0.29 Jy beam⁻¹). The rms noise is 90 μJy beam⁻¹. Dashed contours are overlaid at −5 times the rms noise. Solid contours start at 5 times the rms noise and increase by a factor of 1.4. The resolution is 6″ × 6″. Bottom: SDSS background composite image from bands g, r, and i with the same contours as above. Redshift coloured markers are the same as in Fig. 1. Radio-galaxy candidates (RG-A to RG-D) are marked, along with lines showing the possible orientation of their radio jets and/or tails. Red crosses mark the centres of mass of the two sub-clusters identified by Dahle et al. (2002).