Optical V-band imaging of 3C 293. Left+middle: the various plots show the same image of 3C 293, but with different intensity-scaling and zooming. On the left is shown the larger environment of 3C 293, with overlaid in blue the contours of HI 21 cm emission (levels: 0.04, 0.07, 0.10, 0.13, 0.16, 0.19 Jy bm^-1 × km s^-1). The dashed blue ellipse represents the region where the H i absorption dominates (see Morganti et al. 2003). Even though this H i absorption is spatially unresolved, it is so strong that it dominates over any potential H i emission far beyond the FWHM of the synthesized beam (dashed black ellipse on the bottom-left). The companion galaxies A and B, and feature C, are described in the text. Right: optical spectrum of source A. The Ca II K and H absorption lines confirm that this source is a companion of 3C 293.